diff --git a/resources/profiles/PrusaResearch.idx b/resources/profiles/PrusaResearch.idx
index a108d837fd..3a3e2b333e 100644
--- a/resources/profiles/PrusaResearch.idx
+++ b/resources/profiles/PrusaResearch.idx
@@ -1,4 +1,7 @@
 min_slic3r_version = 2.6.0-alpha5
+1.9.0-alpha4 Updated XL and MK4 profiles. Updated PC Blend Carbon Fiber density.
+1.9.0-alpha3 Updated compatibility condition for MMU1 filaments.
+1.9.0-alpha2 Added profiles for Spectrum filaments.
 1.9.0-alpha1 Added profiles for Original Prusa MK4.
 1.9.0-alpha0 Updated output filename format.
 1.7.0-alpha2 Updated compatibility condition in some filament profiles (Prusa XL).
@@ -8,7 +11,13 @@ min_slic3r_version = 2.6.0-alpha1
 1.6.0-alpha2 Added profile for Prusament PETG Carbon Fiber and Fiberthree F3 PA-GF30 Pro. Updated acceleration settings for Prusa MINI.
 1.6.0-alpha1 Updated FW version notification. Decreased min layer time for PLA.
 1.6.0-alpha0 Default top fill set to monotonic lines. Updated infill/perimeter overlap values. Updated output filename format. Enabled dynamic overhang speeds.
+min_slic3r_version = 2.5.2-rc0
+1.7.3 Updated XL and MK4 profiles. Updated PC Blend Carbon Fiber density.
+1.7.2 Updated compatibility condition for MMU1 filaments.
+1.7.1 Added SLA materials. Updated MK4 and XL profiles.
+1.7.0 Added profiles for Original Prusa MK4.
 min_slic3r_version = 2.5.1-rc0
+1.6.4 Fixed compatibility condition for MMU1 filaments.
 1.6.3 Added SLA materials.
 1.6.2 Updated compatibility condition in some filament profiles (Prusa XL).
 1.6.1 Added filament profile for Prusament PETG Tungsten 75%. Updated Prusa XL profiles.
diff --git a/resources/profiles/PrusaResearch.ini b/resources/profiles/PrusaResearch.ini
index 0194657972..d2528a70a5 100644
--- a/resources/profiles/PrusaResearch.ini
+++ b/resources/profiles/PrusaResearch.ini
@@ -5,7 +5,7 @@
 name = Prusa Research
 # Configuration version of this file. Config file will only be installed, if the config_version differs.
 # This means, the server may force the PrusaSlicer configuration to be downgraded.
-config_version = 1.9.0-alpha1
+config_version = 1.9.0-alpha4
 # Where to get the updates from?
 config_update_url = https://files.prusa3d.com/wp-content/uploads/repository/PrusaSlicer-settings-master/live/PrusaResearch/
 changelog_url = https://files.prusa3d.com/?latest=slicer-profiles&lng=%1%
@@ -2130,6 +2130,7 @@ default_acceleration = 1250
 max_print_speed = 200
 first_layer_extrusion_width = 0.5
 support_material_extrusion_width = 0.37
+top_infill_extrusion_width = 0.4
 gcode_resolution = 0.008
 compatible_printers_condition = printer_model=="XL" and nozzle_diameter[0]==0.4
 
@@ -2162,6 +2163,7 @@ max_print_speed = 200
 first_layer_extrusion_width = 0.5
 gcode_resolution = 0.008
 support_material_extrusion_width = 0.37
+top_infill_extrusion_width = 0.4
 compatible_printers_condition = printer_model=="XL" and nozzle_diameter[0]==0.4
 
 [print:0.20mm SPEED @XL 0.4]
@@ -2192,6 +2194,7 @@ default_acceleration = 1250
 max_print_speed = 200
 first_layer_extrusion_width = 0.5
 support_material_extrusion_width = 0.37
+top_infill_extrusion_width = 0.42
 compatible_printers_condition = printer_model=="XL" and nozzle_diameter[0]==0.4
 
 [print:0.30mm DRAFT @XL 0.4]
@@ -3036,7 +3039,7 @@ inherits = *0.15mm*; *MK4*
 perimeter_speed = 45
 external_perimeter_speed = 25
 small_perimeter_speed = 25
-infill_speed = 90
+infill_speed = 120
 solid_infill_speed = 90
 top_solid_infill_speed = 40
 support_material_contact_distance = 0.2
@@ -3059,6 +3062,7 @@ max_print_speed = 200
 first_layer_extrusion_width = 0.5
 support_material_extrusion_width = 0.37
 gcode_resolution = 0.008
+top_infill_extrusion_width = 0.4
 compatible_printers_condition = printer_model=="MK4" and nozzle_diameter[0]==0.4
 
 [print:0.15mm SPEED @MK4 0.4]
@@ -3089,6 +3093,7 @@ max_print_speed = 200
 first_layer_extrusion_width = 0.5
 support_material_extrusion_width = 0.37
 gcode_resolution = 0.008
+top_infill_extrusion_width = 0.42
 compatible_printers_condition = printer_model=="MK4" and nozzle_diameter[0]==0.4
 
 [print:0.20mm QUALITY @MK4 0.4]
@@ -3096,7 +3101,7 @@ inherits = *0.20mm*; *MK4*
 perimeter_speed = 45
 external_perimeter_speed = 25
 small_perimeter_speed = 25
-infill_speed = 90
+infill_speed = 120
 solid_infill_speed = 90
 top_solid_infill_speed = 40
 support_material_contact_distance = 0.2
@@ -3119,6 +3124,7 @@ max_print_speed = 200
 first_layer_extrusion_width = 0.5
 gcode_resolution = 0.008
 support_material_extrusion_width = 0.37
+top_infill_extrusion_width = 0.4
 compatible_printers_condition = printer_model=="MK4" and nozzle_diameter[0]==0.4
 
 [print:0.20mm SPEED @MK4 0.4]
@@ -3149,6 +3155,7 @@ default_acceleration = 1000
 max_print_speed = 200
 first_layer_extrusion_width = 0.5
 support_material_extrusion_width = 0.37
+top_infill_extrusion_width = 0.42
 compatible_printers_condition = printer_model=="MK4" and nozzle_diameter[0]==0.4
 
 [print:0.30mm DRAFT @MK4 0.4]
@@ -3565,7 +3572,7 @@ compatible_printers_condition = printer_model=="MK4" and nozzle_diameter[0]==0.8
 cooling = 1
 compatible_printers = 
 # For now, all but selected filaments are disabled for the MMU 2.0
-compatible_printers_condition = ! single_extruder_multi_material and printer_notes!~/.*PG.*/
+compatible_printers_condition = ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material) and printer_notes!~/.*PG.*/
 end_filament_gcode = "; Filament-specific end gcode"
 extrusion_multiplier = 1
 filament_loading_speed = 28
@@ -3608,7 +3615,7 @@ min_fan_speed = 100
 temperature = 210
 slowdown_below_layer_time = 10
 start_filament_gcode = "M900 K{if printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.6}0.12{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.8}0.06{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/}0.2{elsif nozzle_diameter[0]==0.8}0.01{elsif nozzle_diameter[0]==0.6}0.04{else}0.05{endif} ; Filament gcode LA 1.5\n{if printer_notes=~/.*PRINTER_MODEL_MINI.*/};{elsif printer_notes=~/.*PRINTER_HAS_BOWDEN.*/}M900 K200{elsif nozzle_diameter[0]==0.6}M900 K18{elsif nozzle_diameter[0]==0.8};{else}M900 K30{endif} ; Filament gcode LA 1.0"
-compatible_printers_condition = ! single_extruder_multi_material and printer_notes!~/.*PG.*/
+compatible_printers_condition = ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material) and printer_notes!~/.*PG.*/
 
 [filament:*PLAPG*]
 start_filament_gcode = "M900 K{if nozzle_diameter[0]==0.4}0.06{elsif nozzle_diameter[0]==0.25}0.14{elsif nozzle_diameter[0]==0.3}0.08{elsif nozzle_diameter[0]==0.35}0.07{elsif nozzle_diameter[0]==0.6}0.03{elsif nozzle_diameter[0]==0.5}0.035{elsif nozzle_diameter[0]==0.8}0.02{else}0{endif} ; Filament gcode\n\nM142 S36 ; set heatbreak target temp"
@@ -3658,7 +3665,7 @@ start_filament_gcode = "M900 K{if printer_notes=~/.*PRINTER_MODEL_MINI.*/ and no
 temperature = 240
 filament_retract_length = 1
 filament_retract_lift = 0.2
-compatible_printers_condition = printer_model!="MK2SMM" and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = printer_model!="MK2SMM" and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:*PET06*]
 inherits = *PET*
@@ -3700,7 +3707,7 @@ slowdown_below_layer_time = 18
 filament_retract_length = 0.8
 
 [filament:*04PLUS*]
-compatible_printers_condition = nozzle_diameter[0]>=0.4 and ! single_extruder_multi_material and printer_notes!~/.*PG.*/
+compatible_printers_condition = nozzle_diameter[0]>=0.4 and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material) and printer_notes!~/.*PG.*/
 
 [filament:*04PLUSPG*]
 compatible_printers_condition = nozzle_diameter[0]>=0.4 and nozzle_diameter[0]!=0.6 and nozzle_diameter[0]!=0.8 and printer_notes=~/.*PG.*/
@@ -3815,7 +3822,7 @@ compatible_printers_condition = printer_model!="MINI" and printer_notes!~/.*PG.*
 
 [filament:*ABSPG*]
 compatible_printers_condition = printer_model=="XL" and nozzle_diameter[0]!=0.6 and nozzle_diameter[0]!=0.8
-filament_max_volumetric_speed = 14
+filament_max_volumetric_speed = 12
 start_filament_gcode = "M900 K{if nozzle_diameter[0]==0.4}0.04{elsif nozzle_diameter[0]==0.25}0.1{elsif nozzle_diameter[0]==0.3}0.06{elsif nozzle_diameter[0]==0.35}0.05{elsif nozzle_diameter[0]==0.5}0.03{elsif nozzle_diameter[0]==0.6}0.02{elsif nozzle_diameter[0]==0.8}0.01{else}0{endif} ; Filament gcode\n\nM142 S40 ; set heatbreak target temp"
 filament_cooling_final_speed = 50 
 filament_cooling_initial_speed = 10
@@ -3869,7 +3876,7 @@ compatible_printers_condition = printer_model=="XL" and nozzle_diameter[0]==0.6
 
 [filament:*PC08PG*]
 inherits = *PCPG*
-filament_max_volumetric_speed = 20
+filament_max_volumetric_speed = 18
 compatible_printers_condition = printer_model=="XL" and nozzle_diameter[0]==0.8
 
 [filament:*PCMK4*]
@@ -3885,7 +3892,7 @@ compatible_printers_condition = printer_model=="MK4" and nozzle_diameter[0]==0.6
 
 [filament:*PC08MK4*]
 inherits = *PCMK4*
-filament_max_volumetric_speed = 20
+filament_max_volumetric_speed = 18
 compatible_printers_condition = printer_model=="MK4" and nozzle_diameter[0]==0.8
 
 [filament:*PAPG*]
@@ -4196,7 +4203,7 @@ start_filament_gcode = "M900 K{if printer_notes=~/.*PRINTER_MODEL_MINI.*/ and no
 temperature = 260
 filament_retract_length = nil
 filament_retract_lift = 0.4
-compatible_printers_condition = nozzle_diameter[0]>=0.4 and printer_model!="MK2SMM" and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]>=0.4 and printer_model!="MK2SMM" and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:ColorFabb XT-CF20 @PG]
 inherits = ColorFabb XT-CF20; *PETPG*; *04PLUSPG*
@@ -4317,7 +4324,7 @@ filament_colour = #804040
 filament_max_volumetric_speed = 6
 first_layer_temperature = 260
 temperature = 260
-compatible_printers_condition = nozzle_diameter[0]>=0.4 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]>=0.4 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Kimya ABS Carbon @PG]
 inherits = Kimya ABS Carbon; *ABSPG*; *04PLUSPG*
@@ -4577,7 +4584,7 @@ filament_type = PC
 filament_colour = #DEE0E6
 filament_max_volumetric_speed = 8
 filament_retract_lift = 0.2
-compatible_printers_condition = printer_notes!~/.*PRINTER_MODEL_MK(2|2.5).*/ and nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = printer_notes!~/.*PRINTER_MODEL_MK(2|2.5).*/ and nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 start_filament_gcode = "M900 K{if printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.6}0.12{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.8}0.06{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/}0.2{elsif nozzle_diameter[0]==0.8}0.02{elsif nozzle_diameter[0]==0.6}0.04{else}0.07{endif} ; Filament gcode LA 1.5\n{if printer_notes=~/.*PRINTER_MODEL_MINI.*/};{elsif printer_notes=~/.*PRINTER_HAS_BOWDEN.*/}M900 K200{elsif nozzle_diameter[0]==0.6}M900 K24{elsif nozzle_diameter[0]==0.8};{else}M900 K45{endif} ; Filament gcode LA 1.0"
 
 [filament:Prusament PC Blend @PG]
@@ -4609,12 +4616,12 @@ inherits = Prusament PC Blend
 first_layer_bed_temperature = 105
 bed_temperature = 110
 disable_fan_first_layers = 6
-compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_notes=~/.*PRINTER_MODEL_MK(2|2.5).*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_notes=~/.*PRINTER_MODEL_MK(2|2.5).*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Prusament PC Blend Carbon Fiber]
 inherits = Prusament PC Blend
 filament_cost = 90.73 
-filament_density = 1.16
+filament_density = 1.22
 extrusion_multiplier = 1.04
 first_layer_temperature = 285
 temperature = 285
@@ -4623,7 +4630,7 @@ fan_below_layer_time = 10
 filament_colour = #BBBBBB
 filament_retract_length = nil
 filament_retract_lift = nil
-compatible_printers_condition = printer_notes!~/.*PRINTER_MODEL_MK(2|2.5).*/ and nozzle_diameter[0]>=0.4 and nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = printer_notes!~/.*PRINTER_MODEL_MK(2|2.5).*/ and nozzle_diameter[0]>=0.4 and nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Prusament PC Blend Carbon Fiber @PG]
 inherits = Prusament PC Blend Carbon Fiber; *PCPG*
@@ -4667,7 +4674,7 @@ temperature = 285
 first_layer_bed_temperature = 90
 bed_temperature = 115
 fan_below_layer_time = 10
-compatible_printers_condition = printer_notes!~/.*PRINTER_MODEL_MK(2|2.5).*/ and nozzle_diameter[0]>=0.4 and nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = printer_notes!~/.*PRINTER_MODEL_MK(2|2.5).*/ and nozzle_diameter[0]>=0.4 and nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Prusament PA11 Carbon Fiber @PG]
 inherits = Prusament PA11 Carbon Fiber; *PCPG*
@@ -4786,7 +4793,7 @@ inherits = *ABSC*
 filament_vendor = Generic
 filament_cost = 27.82
 filament_density = 1.04
-compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Generic ABS @PG]
 inherits = Generic ABS; *ABSPG*
@@ -4923,7 +4930,7 @@ renamed_from = "Generic PET"
 filament_vendor = Generic
 filament_cost = 27.82
 filament_density = 1.27
-compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_model!="MK2SMM" and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_model!="MK2SMM" and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Generic PETG @PG]
 inherits = Generic PETG; *PETPG*
@@ -5393,7 +5400,7 @@ filament_retract_lift = 0.4
 filament_max_volumetric_speed = 4
 start_filament_gcode = "M900 K{if printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.6}0.12{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.8}0.06{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/}0.2{elsif nozzle_diameter[0]==0.8}0.02{elsif nozzle_diameter[0]==0.6}0.04{else}0.08{endif} ; Filament gcode LA 1.5\n{if printer_notes=~/.*PRINTER_MODEL_MINI.*/};{elsif printer_notes=~/.*PRINTER_HAS_BOWDEN.*/}M900 K200{elsif nozzle_diameter[0]==0.6}M900 K24{elsif nozzle_diameter[0]==0.8};{else}M900 K45{endif} ; Filament gcode LA 1.0"
 filament_spool_weight = 0
-compatible_printers_condition = printer_notes!~/.*PRINTER_MODEL_MK(2|2.5).*/ and nozzle_diameter[0]>=0.4 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and printer_model!="MK2SMM" and ! single_extruder_multi_material
+compatible_printers_condition = printer_notes!~/.*PRINTER_MODEL_MK(2|2.5).*/ and nozzle_diameter[0]>=0.4 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and printer_model!="MK2SMM" and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:addnorth Adura X @PG]
 inherits = addnorth Adura X; *PETPG*
@@ -5647,7 +5654,7 @@ filament_retract_length = 1.4
 filament_max_volumetric_speed = 5
 filament_spool_weight = 0
 filament_notes = "Please use a nozzle that is resistant to abrasive filaments, like hardened steel."
-compatible_printers_condition = nozzle_diameter[0]>=0.4 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and printer_model!="MK2SMM" and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]>=0.4 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and printer_model!="MK2SMM" and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:addnorth Rigid X @PG]
 inherits = addnorth Rigid X; *PETPG*; *04PLUSPG*
@@ -5693,7 +5700,7 @@ slowdown_below_layer_time = 15
 min_print_speed = 20
 filament_spool_weight = 0
 filament_retract_length = 1
-compatible_printers_condition = printer_model!="MK2SMM" and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = printer_model!="MK2SMM" and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:addnorth Textura @PG]
 inherits = addnorth Textura; *PLAPG*
@@ -5730,7 +5737,7 @@ disable_fan_first_layers = 3
 fan_below_layer_time = 60
 slowdown_below_layer_time = 15
 bridge_fan_speed = 20
-compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Filamentworld ABS @PG]
 inherits = Filamentworld ABS; *ABSPG*
@@ -5827,7 +5834,7 @@ filament_vendor = Filament PM
 filament_cost = 27.82
 filament_density = 1.27
 filament_spool_weight = 230
-compatible_printers_condition = nozzle_diameter[0]!=0.6 and printer_model!="MK2SMM" and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.6 and printer_model!="MK2SMM" and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Filament PM PETG @PG]
 inherits = Filament PM PETG; *PETPG*
@@ -5843,7 +5850,7 @@ inherits = *PLA*
 filament_vendor = Generic
 filament_cost = 25.4
 filament_density = 1.24
-compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Generic PLA @PG]
 inherits = Generic PLA; *PLAPG*
@@ -6092,6 +6099,220 @@ inherits = Spectrum PLA; *PLA06PG*
 [filament:Spectrum PLA @PG 0.8]
 inherits = Spectrum PLA; *PLA08PG*
 
+[filament:Spectrum PETG Matt]
+inherits = *PET*
+filament_vendor = Spectrum
+bed_temperature = 90
+bridge_fan_speed = 50
+extrusion_multiplier = 1.1
+disable_fan_first_layers = 1
+full_fan_speed_layer = 1
+fan_always_on = 1
+fan_below_layer_time = 20
+filament_colour = #FF8000
+filament_max_volumetric_speed = 8
+filament_type = PETG
+first_layer_bed_temperature = 85
+first_layer_temperature = 230
+max_fan_speed = 100
+min_fan_speed = 30
+temperature = 240
+filament_density = 1.35
+
+[filament:Spectrum PETG Matt @PG]
+inherits = Spectrum PETG Matt; *PETPG*
+
+[filament:Spectrum PETG Matt @PG 0.6]
+inherits = Spectrum PETG Matt @PG; *PET06PG*
+
+[filament:Spectrum PETG Matt @PG 0.8]
+inherits = Spectrum PETG Matt @PG; *PET08PG*
+
+[filament:Spectrum PETG Matt @MINI]
+inherits = Spectrum PETG Matt; *PETMINI*
+
+[filament:Spectrum PETG HT100]
+inherits = *PET*
+filament_vendor = Spectrum
+bed_temperature = 105
+bridge_fan_speed = 50
+extrusion_multiplier = 1
+disable_fan_first_layers = 1
+full_fan_speed_layer = 1
+fan_always_on = 1
+fan_below_layer_time = 20
+filament_colour = #FF8000
+filament_max_volumetric_speed = 8
+filament_type = PETG
+first_layer_bed_temperature = 105
+first_layer_temperature = 250
+max_fan_speed = 100
+min_fan_speed = 30
+temperature = 250
+filament_density = 1.24
+
+[filament:Spectrum PETG HT100 @PG]
+inherits = Spectrum PETG HT100; *PETPG*
+
+[filament:Spectrum PETG HT100 @PG 0.6]
+inherits = Spectrum PETG HT100 @PG; *PET06PG*
+
+[filament:Spectrum PETG HT100 @PG 0.8]
+inherits = Spectrum PETG HT100 @PG; *PET08PG*
+
+[filament:Spectrum PETG HT100 @MINI]
+inherits = Spectrum PETG HT100; *PETMINI*
+bed_temperature = 100
+first_layer_bed_temperature = 100
+
+[filament:Spectrum GreenyHT]
+inherits = *PLA*
+filament_vendor = Spectrum
+first_layer_temperature = 205   
+first_layer_bed_temperature = 45
+temperature = 205
+bed_temperature = 45
+bridge_fan_speed = 50
+extrusion_multiplier = 1.0
+disable_fan_first_layers = 1
+full_fan_speed_layer = 1
+fan_always_on = 1
+fan_below_layer_time = 20
+filament_colour = #FF8000
+filament_max_volumetric_speed = 8
+filament_type = PLA
+max_fan_speed = 100
+min_fan_speed = 30
+filament_density = 1.54
+
+[filament:Spectrum GreenyHT @PG]
+inherits = Spectrum GreenyHT; *PLAPG*
+
+[filament:Spectrum GreenyHT @PG 0.6]
+inherits = Spectrum GreenyHT @PG; *PLA06PG*
+
+[filament:Spectrum GreenyHT @PG 0.8]
+inherits = Spectrum GreenyHT @PG; *PLA08PG*
+
+[filament:Spectrum ASA 275]
+inherits = *ABSC*
+filament_vendor = Spectrum
+first_layer_temperature = 237
+first_layer_bed_temperature = 80
+temperature = 237
+bed_temperature = 80
+extrusion_multiplier = 0.98
+filament_type = ASA
+filament_density = 1.24
+
+[filament:Spectrum ASA 275 @PG]
+inherits = Spectrum ASA 275; *ABSPG*
+compatible_printers_condition = nozzle_diameter[0]!=0.6 and nozzle_diameter[0]!=0.8 and printer_notes=~/.*PG.*/ and ! single_extruder_multi_material
+
+[filament:Spectrum ASA 275 @PG 0.6]
+inherits = Spectrum ASA 275 @PG; *ABS06PG*
+compatible_printers_condition = nozzle_diameter[0]==0.6 and printer_notes=~/.*PG.*/ and ! single_extruder_multi_material
+
+[filament:Spectrum ASA 275 @PG 0.8]
+inherits = Spectrum ASA 275 @PG; *ABS08PG*
+compatible_printers_condition = nozzle_diameter[0]==0.8 and printer_notes=~/.*PG.*/ and ! single_extruder_multi_material
+
+[filament:Spectrum ASA 275 @MINI]
+inherits = Spectrum ASA 275; *ABSMINI*
+temperature = 235
+bed_temperature = 80
+extrusion_multiplier = 1
+
+[filament:Spectrum ASA Kevlar]
+inherits = *ABSC*
+filament_vendor = Spectrum
+temperature = 250
+bed_temperature = 105
+extrusion_multiplier = 1.04
+filament_type = ASA
+filament_density = 1.24
+compatible_printers_condition = nozzle_diameter[0]>=0.4 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
+
+[filament:Spectrum ASA Kevlar @PG]
+inherits = Spectrum ASA Kevlar; *ABSPG*
+compatible_printers_condition = nozzle_diameter[0]>=0.4 and nozzle_diameter[0]!=0.6 and nozzle_diameter[0]!=0.8 and printer_model=="XL"
+
+[filament:Spectrum ASA Kevlar @PG 0.6]
+inherits = Spectrum ASA Kevlar @PG; *ABS06PG*
+
+[filament:Spectrum ASA Kevlar @PG 0.8]
+inherits = Spectrum ASA Kevlar @PG; *ABS08PG*
+
+[filament:Spectrum ASA Kevlar @MK4]
+inherits = Spectrum ASA Kevlar; *ABSMK4*
+compatible_printers_condition = nozzle_diameter[0]>=0.4 and nozzle_diameter[0]!=0.6 and nozzle_diameter[0]!=0.8 and printer_model=="MK4"
+
+[filament:Spectrum ASA Kevlar @MK4 0.6]
+inherits = Spectrum ASA Kevlar @MK4; *ABS06MK4*
+
+[filament:Spectrum ASA Kevlar @MK4 0.8]
+inherits = Spectrum ASA Kevlar @MK4; *ABS08MK4*
+
+[filament:Spectrum ASA Kevlar @MINI]
+inherits = Spectrum ASA Kevlar; *ABSMINI*
+temperature = 250
+bed_temperature = 100
+extrusion_multiplier = 1.03
+compatible_printers_condition = nozzle_diameter[0]>=0.4 and printer_model=="MINI"
+
+[filament:Spectrum Tough PLA]
+inherits = *PLA*
+filament_vendor = Spectrum
+temperature = 235
+bed_temperature = 45
+extrusion_multiplier = 0.95
+filament_type = PLA Tough
+filament_density = 1.24
+
+[filament:Spectrum Tough PLA @PG]
+inherits = Spectrum Tough PLA; *PLAPG*
+
+[filament:Spectrum Tough PLA @PG 0.6]
+inherits = Spectrum Tough PLA @PG; *PLA06PG*
+
+[filament:Spectrum Tough PLA @PG 0.8]
+inherits = Spectrum Tough PLA @PG; *PLA08PG*
+
+[filament:Spectrum PLA PRO]
+inherits = *PLA*
+filament_vendor = Spectrum
+filament_type = PLA
+filament_density = 1.22
+
+[filament:Spectrum PLA PRO @PG]
+inherits = Spectrum PLA PRO; *PLAPG*
+
+[filament:Spectrum PLA PRO @PG 0.6]
+inherits = Spectrum PLA PRO @PG; *PLA06PG*
+
+[filament:Spectrum PLA PRO @PG 0.8]
+inherits = Spectrum PLA PRO @PG; *PLA08PG*
+
+[filament:Spectrum PCTG]
+inherits = *PET*
+filament_vendor = Spectrum
+filament_type = PCTG
+temperature = 240
+bed_temperature = 90
+filament_density = 1.27
+
+[filament:Spectrum PCTG @PG]
+inherits = Spectrum PCTG; *PETPG*
+
+[filament:Spectrum PCTG @PG 0.6]
+inherits = Spectrum PCTG @PG; *PET06PG*
+
+[filament:Spectrum PCTG @PG 0.8]
+inherits = Spectrum PCTG @PG; *PET08PG*
+
+[filament:Spectrum PCTG @MINI]
+inherits = Spectrum PCTG; *PETMINI*
+
 [filament:Generic FLEX]
 inherits = *FLEX*
 filament_vendor = Generic
@@ -6596,7 +6817,7 @@ extrusion_multiplier = 0.95
 filament_density = 1.1
 first_layer_bed_temperature = 105
 bed_temperature = 100
-compatible_printers_condition = nozzle_diameter[0]>=0.4 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]>=0.4 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Filatech FilaCarbon @PG]
 inherits = Filatech FilaCarbon; *ABSPG*; *04PLUSPG*
@@ -6698,7 +6919,7 @@ first_layer_temperature = 230
 first_layer_bed_temperature = 100
 temperature = 225
 bed_temperature = 110
-compatible_printers_condition = printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Filatech HIPS @PG]
 inherits = Filatech HIPS; *ABSPG*
@@ -6755,7 +6976,7 @@ cooling = 0
 bridge_fan_speed = 25
 filament_type = PA
 filament_max_volumetric_speed = 8
-compatible_printers_condition = printer_notes!~/.*PRINTER_MODEL_MK(2|2.5).*/ and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = printer_notes!~/.*PRINTER_MODEL_MK(2|2.5).*/ and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Filatech PA @PG]
 inherits = Filatech PA; *ABSPG*
@@ -7235,7 +7456,7 @@ min_fan_speed = 20
 max_fan_speed = 20
 bridge_fan_speed = 30
 disable_fan_first_layers = 4
-compatible_printers_condition = printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 filament_notes = "Material Description\nUltrafuse® PC/ABS FR Black is a V-0 flame retardant blend of Polycarbonate and ABS – two of the most used thermoplastics for engineering & electrical applications. The combination of these two materials results in a premium material with a mix of the excellent mechanical properties of PC and the comparably low printing temperature of ABS. Combined with a halogen free flame retardant, parts printed with Ultrafuse® PC/ABS FR Black feature great tensile and impact strength, higher thermal resistance than ABS and can fulfill the requirements of the UL94 V-0 standard.\n\nPrinting Recommendations:\nApply Magigoo PC to a clean build plate to improve adhesion."
 start_filament_gcode = "M900 K{if printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.6}0.12{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.8}0.06{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/}0.2{elsif nozzle_diameter[0]==0.8}0.02{elsif nozzle_diameter[0]==0.6}0.04{else}0.07{endif} ; Filament gcode LA 1.5\n{if printer_notes=~/.*PRINTER_MODEL_MINI.*/};{elsif printer_notes=~/.*PRINTER_HAS_BOWDEN.*/}M900 K200{elsif nozzle_diameter[0]==0.6}M900 K24{elsif nozzle_diameter[0]==0.8};{else}M900 K45{endif} ; Filament gcode LA 1.0"
 
@@ -7670,7 +7891,7 @@ filament_vendor = Made for Prusa
 filament_cost = 27.82
 filament_density = 1.08
 filament_spool_weight = 230
-compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Prusa ABS @PG]
 inherits = Prusa ABS; *ABSPG*
@@ -7881,7 +8102,7 @@ start_filament_gcode = "M900 K{if printer_notes=~/.*PRINTER_MODEL_MINI.*/ and no
 [filament:Prusament PC Blend Carbon Fiber @MMU2]
 inherits = Prusament PC Blend @MMU2
 filament_cost = 90.73
-filament_density = 1.16
+filament_density = 1.22
 extrusion_multiplier = 1.04
 fan_below_layer_time = 10
 first_layer_temperature = 280
@@ -7925,7 +8146,7 @@ max_fan_speed = 20
 min_fan_speed = 20
 start_filament_gcode = "M900 K{if printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.6}0.12{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.8}0.06{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/}0.2{elsif nozzle_diameter[0]==0.8}0.01{elsif nozzle_diameter[0]==0.6}0.03{else}0.04{endif} ; Filament gcode LA 1.5\n{if printer_notes=~/.*PRINTER_MODEL_MINI.*/};{elsif printer_notes=~/.*PRINTER_HAS_BOWDEN.*/}M900 K200{elsif nozzle_diameter[0]==0.6}M900 K12{elsif nozzle_diameter[0]==0.8};{else}M900 K20{endif} ; Filament gcode LA 1.0"
 temperature = 220
-compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Generic HIPS]
 inherits = *ABS*
@@ -7945,7 +8166,7 @@ max_fan_speed = 20
 min_fan_speed = 20
 start_filament_gcode = "M900 K{if printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.6}0.12{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.8}0.06{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/}0.2{elsif nozzle_diameter[0]==0.8}0.01{elsif nozzle_diameter[0]==0.6}0.03{else}0.04{endif} ; Filament gcode LA 1.5\n{if printer_notes=~/.*PRINTER_MODEL_MINI.*/};{elsif printer_notes=~/.*PRINTER_HAS_BOWDEN.*/}M900 K200{elsif nozzle_diameter[0]==0.6}M900 K12{elsif nozzle_diameter[0]==0.8};{else}M900 K20{endif} ; Filament gcode LA 1.0"
 temperature = 230
-compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Generic HIPS @PG]
 inherits = Generic HIPS; *ABSPG*
@@ -7973,7 +8194,7 @@ filament_vendor = Made for Prusa
 filament_cost = 27.82
 filament_density = 1.27
 filament_spool_weight = 230
-compatible_printers_condition = nozzle_diameter[0]!=0.6 and nozzle_diameter[0]!=0.8 and printer_model!="MK2SMM" and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.6 and nozzle_diameter[0]!=0.8 and printer_model!="MK2SMM" and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Prusa PETG @PG]
 inherits = Prusa PETG; *PETPG*
@@ -8239,7 +8460,7 @@ filament_vendor = Made for Prusa
 filament_cost = 27.82
 filament_density = 1.24
 filament_spool_weight = 230
-compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Prusa PLA @PG]
 inherits = Prusa PLA; *PLAPG*
@@ -9350,7 +9571,7 @@ filament_cost = 36.29
 filament_density = 1.24
 filament_spool_weight = 201
 filament_notes = "Affordable filament for everyday printing in premium quality manufactured in-house by Josef Prusa"
-compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Prusament PLA @PG]
 inherits = Prusament PLA; *PLAPG*
@@ -9377,7 +9598,7 @@ filament_max_volumetric_speed = 8
 filament_type = PVB
 filament_soluble = 1
 filament_colour = #FFFF6F
-compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]!=0.8 and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 slowdown_below_layer_time = 20
 start_filament_gcode = "M900 K{if printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.6}0.12{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.8}0.06{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/}0.2{elsif nozzle_diameter[0]==0.8}0.02{elsif nozzle_diameter[0]==0.6}0.05{else}0.08{endif} ; Filament gcode LA 1.5\n{if printer_notes=~/.*PRINTER_MODEL_MINI.*/};{elsif printer_notes=~/.*PRINTER_HAS_BOWDEN.*/}M900 K200{elsif nozzle_diameter[0]==0.6}M900 K24{elsif nozzle_diameter[0]==0.8};{else}M900 K45{endif} ; Filament gcode LA 1.0"
 
@@ -9557,7 +9778,7 @@ temperature = 260
 max_fan_speed = 0
 min_fan_speed = 0
 start_filament_gcode = "M900 K{if printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.6}0.12{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/ and nozzle_diameter[0]==0.8}0.06{elsif printer_notes=~/.*PRINTER_MODEL_MINI.*/}0.2{elsif nozzle_diameter[0]==0.8}0.02{elsif nozzle_diameter[0]==0.6}0.04{else}0.08{endif} ; Filament gcode LA 1.5\n{if printer_notes=~/.*PRINTER_MODEL_MINI.*/};{elsif printer_notes=~/.*PRINTER_HAS_BOWDEN.*/}M900 K200{elsif nozzle_diameter[0]==0.6}M900 K24{elsif nozzle_diameter[0]==0.8};{else}M900 K45{endif} ; Filament gcode LA 1.0"
-compatible_printers_condition = printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:Taulman Bridge @PG]
 inherits = Taulman Bridge; *ABSPG*
@@ -9779,7 +10000,7 @@ temperature = 285
 first_layer_bed_temperature = 90
 bed_temperature = 90
 fan_below_layer_time = 10
-compatible_printers_condition = printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 max_fan_speed = 15
 min_fan_speed = 15
 filament_type = PA
@@ -10009,7 +10230,7 @@ start_filament_gcode = "M900 K{if printer_notes=~/.*PRINTER_MODEL_MINI.*/ and no
 temperature = 235
 filament_wipe = 0
 filament_retract_lift = 0
-compatible_printers_condition = nozzle_diameter[0]>=0.35 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! single_extruder_multi_material
+compatible_printers_condition = nozzle_diameter[0]>=0.35 and printer_model!="MINI" and printer_notes!~/.*PG.*/ and ! (printer_notes=~/.*PRINTER_VENDOR_PRUSA3D.*/ and printer_notes=~/.*PRINTER_MODEL_MK(2.5|3).*/ and single_extruder_multi_material)
 
 [filament:FormFutura Centaur PP @PG]
 inherits = FormFutura Centaur PP; *PETPG*
@@ -10468,7 +10689,7 @@ compatible_printers_condition = printer_model=="MINI" and nozzle_diameter[0]!=0.
 [filament:Prusament PC Blend Carbon Fiber @MINI]
 inherits = Prusament PC Blend @MINI
 filament_cost = 90.73
-filament_density = 1.16
+filament_density = 1.22
 extrusion_multiplier = 1.04
 first_layer_temperature = 280
 temperature = 280
diff --git a/src/libslic3r/Emboss.cpp b/src/libslic3r/Emboss.cpp
index 92ee42c62e..ac7b9302e7 100644
--- a/src/libslic3r/Emboss.cpp
+++ b/src/libslic3r/Emboss.cpp
@@ -835,10 +835,10 @@ const Glyph* priv::get_glyph(
             glyph.shape = Slic3r::union_ex(offset_ex(glyph.shape, delta));
         }
         if (font_prop.skew.has_value()) {
-            const float &ratio = *font_prop.skew;
+            double ratio = *font_prop.skew;
             auto skew = [&ratio](Polygon &polygon) {
                 for (Slic3r::Point &p : polygon.points)
-                    p.x() += static_cast<int>(std::round(p.y() * ratio));
+                    p.x() += static_cast<Point::coord_type>(std::round(p.y() * ratio));
             };
             for (ExPolygon &expolygon : glyph.shape) {
                 skew(expolygon.contour);
@@ -1361,10 +1361,9 @@ std::string Emboss::create_range_text(const std::string &text,
 
 double Emboss::get_text_shape_scale(const FontProp &fp, const FontFile &ff)
 {
-    const std::optional<unsigned int> &cn = fp.collection_number;
-    unsigned int font_index  = (cn.has_value()) ? *cn : 0;
-    int unit_per_em = ff.infos[font_index].unit_per_em;
-    double scale = fp.size_in_mm / unit_per_em;
+    size_t font_index  = fp.collection_number.value_or(0);
+    const FontFile::Info &info = ff.infos[font_index];
+    double scale  = fp.size_in_mm / (double) info.unit_per_em;
     // Shape is scaled for store point coordinate as integer
     return scale * SHAPE_SCALE;
 }
diff --git a/src/libslic3r/Layer.cpp b/src/libslic3r/Layer.cpp
index 7802fe9833..199caf0d04 100644
--- a/src/libslic3r/Layer.cpp
+++ b/src/libslic3r/Layer.cpp
@@ -78,16 +78,22 @@ void Layer::make_slices()
     ClipperLib::ClipperOffset   co;
     ClipperLib::Paths           out2;
 
-    static constexpr const float delta = ClipperSafetyOffset; // *10.f;
+    // Top / bottom surfaces must overlap more than 2um to be chained into a Z graph.
+    // Also a larger offset will likely be more robust on non-manifold input polygons.
+    static constexpr const float delta = scaled<float>(0.001);
     co.MiterLimit = scaled<double>(3.);
 // Use the default zero edge merging distance. For this kind of safety offset the accuracy of normal direction is not important.
 //    co.ShortestEdgeLength = delta * ClipperOffsetShortestEdgeFactor;
+    static constexpr const double accept_area_threshold_ccw = sqr(scaled<double>(0.1 * delta));
+    // Such a small hole should not survive the shrinkage, it should grow over 
+    static constexpr const double accept_area_threshold_cw  = sqr(scaled<double>(0.2 * delta));
 
     for (const ExPolygon &expoly : expolygons) {
         contours.clear();
         co.Clear();
         co.AddPath(expoly.contour.points, ClipperLib::jtMiter, ClipperLib::etClosedPolygon);
         co.Execute(contours, - delta);
+        size_t num_prev = out.size();
         if (! contours.empty()) {
             holes.clear();
             for (const Polygon &hole : expoly.holes) {
@@ -109,13 +115,46 @@ void Layer::make_slices()
                 clipper.Execute(ClipperLib::ctDifference, contours, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
             }
             for (const auto &contour : contours) {
-                out.emplace_back();
-                ClipperLib_Z::Path &path = out.back();
-                path.reserve(contour.size());
-                for (const Point &p : contour)
-                    path.push_back({ p.x(), p.y(), isrc });
+                bool accept = true;
+                // Trying to get rid of offset artifacts, that may be created due to numerical issues in offsetting algorithm
+                // or due to self-intersections in the source polygons.
+                //FIXME how reliable is it? Is it helpful or harmful? It seems to do more harm than good as it tends to punch holes
+                // into existing ExPolygons.
+#if 0
+                if (contour.size() < 8) {
+                    // Only accept contours with area bigger than some threshold.
+                    double a = ClipperLib::Area(contour);
+                    // Polygon has to be bigger than some threshold to be accepted.
+                    // Hole to be accepted has to have an area slightly bigger than the non-hole, so it will not happen due to rounding errors,
+                    // that a hole will be accepted without its outer contour.
+                    accept = a > 0 ? a > accept_area_threshold_ccw : a < - accept_area_threshold_cw;
+                }
+#endif
+                if (accept) {
+                    out.emplace_back();
+                    ClipperLib_Z::Path &path = out.back();
+                    path.reserve(contour.size());
+                    for (const Point &p : contour)
+                        path.push_back({ p.x(), p.y(), isrc });
+                }
             }
         }
+#if 0 // #ifndef NDEBUG
+        // Test whether the expolygons in a single layer overlap.
+        Polygons test;
+        for (size_t i = num_prev; i < out.size(); ++ i)
+            test.emplace_back(ClipperZUtils::from_zpath(out[i]));
+        Polygons outside = diff(test, to_polygons(expoly));
+        if (! outside.empty()) {
+            BoundingBox bbox(get_extents(expoly));
+            bbox.merge(get_extents(test));
+            SVG svg(debug_out_path("expolygons_to_zpaths_shrunk-self-intersections.svg").c_str(), bbox);
+            svg.draw(expoly, "blue");
+            svg.draw(test, "green");
+            svg.draw(outside, "red");
+        }
+        assert(outside.empty());
+#endif // NDEBUG
         ++ isrc;
     }
 
@@ -164,121 +203,36 @@ static void connect_layer_slices(
             if (polynode.Contour.size() >= 3) {
                 // If there is an intersection point, it should indicate which contours (one from layer below, the other from layer above) intersect.
                 // Otherwise the contour is fully inside another contour.
-                int32_t i = -1, j = -1;
-                for (int icontour = 0; icontour <= polynode.ChildCount(); ++ icontour) {
-                    const ClipperLib_Z::Path &contour = icontour == 0 ? polynode.Contour : polynode.Childs[icontour - 1]->Contour;
-                    if (contour.size() >= 3) {
-                        for (const ClipperLib_Z::IntPoint &pt : contour) {
-                            j = pt.z();
-                            if (j < 0) {
-                                const auto &intersection = m_intersections[-j - 1];
-                                assert(intersection.first <= intersection.second);
-                                if (intersection.second < m_offset_above) {
-                                    // Ignore intersection of polygons on the 1st layer.
-                                    assert(intersection.first >= m_offset_below);
-                                    j = i;
-                                } else if (intersection.first >= m_offset_above) {
-                                    // Ignore intersection of polygons on the 2nd layer
-                                    assert(intersection.second < m_offset_end);
-                                    j = i;
-                                } else {
-                                    std::tie(i, j) = m_intersections[-j - 1];
-                                    assert(assert_intersection_valid(i, j));
-                                    goto end;
-                                }
-                            } else if (i == -1) {
-                                // First source contour of this expolygon was found.
-                                i = j;
-                            } else if (i != j) {
-                                // Second source contour of this expolygon was found.
-                                if (i > j)
-                                    std::swap(i, j);
-                                assert(assert_intersection_valid(i, j));
-                                goto end;
-                            }
-                        }
+                auto [i, j] = this->find_top_bottom_contour_ids_strict(polynode);
+                bool found = false;
+                if (i < 0 && j < 0) {
+                    // This should not happen. It may only happen if the source contours had just self intersections or intersections with contours at the same layer.
+                    // We may safely ignore such cases where the intersection area is meager.
+                    double a = ClipperLib_Z::Area(polynode.Contour);
+                    if (a < sqr(scaled<double>(0.001))) {
+                        // Ignore tiny overlaps. They are not worth resolving.
+                    } else {
+                        // We should not ignore large cases. Try to resolve the conflict by a majority of references.
+                        std::tie(i, j) = this->find_top_bottom_contour_ids_approx(polynode);
+                        // At least top or bottom should be resolved.
+                        assert(i >= 0 || j >= 0);
                     }
                 }
-            end:
-                bool found = false;
-                if (i == -1) {
-                    // This should not happen. It may only happen if the source contours had just self intersections or intersections with contours at the same layer.
-                    assert(false);
-                } else if (i == j) {
-                    // The contour is completely inside another contour.
-                    Point pt(polynode.Contour.front().x(), polynode.Contour.front().y());
-                    if (i < m_offset_above) {
-                        // Index of an island below. Look-it up in the island above.
-                        assert(i >= m_offset_below);
-                        i -= m_offset_below;
-                        for (int l = int(m_above.lslices_ex.size()) - 1; l >= 0; -- l) {
-                            LayerSlice &lslice = m_above.lslices_ex[l];
-                            if (lslice.bbox.contains(pt) && m_above.lslices[l].contains(pt)) {
-                                found = true;
-                                j = l;
-                                assert(i >= 0 && i < m_below.lslices_ex.size());
-                                assert(j >= 0 && j < m_above.lslices_ex.size());
-                                break;
-                            }
-                        }
-                        //FIXME remove the following block one day, it should not be needed.
-                        // The following shall not happen now as the source expolygons are being shrunk a bit before intersecting,
-                        // thus each point of each intersection polygon should fit completely inside one of the original (unshrunk) expolygons.
-                        assert(found);
-                        if (!found) {
-                            // The check above might sometimes fail when the polygons overlap only on points, which causes the clipper to detect no intersection.
-                            // The problem happens rarely, mostly on simple polygons (in terms of number of points), but regardless of size!
-                            // example of failing link on two layers, each with single polygon without holes.
-                            // layer A = Polygon{(-24931238,-11153865),(-22504249,-8726874),(-22504249,11477151),(-23261469,12235585),(-23752371,12727276),(-25002495,12727276),(-27502745,10227026),(-27502745,-12727274),(-26504645,-12727274)}
-                            // layer B = Polygon{(-24877897,-11100524),(-22504249,-8726874),(-22504249,11477151),(-23244827,12218916),(-23752371,12727276),(-25002495,12727276),(-27502745,10227026),(-27502745,-12727274),(-26504645,-12727274)}
-                            // note that first point is not identical, and the check above picks (-24877897,-11100524) as the first contour point (polynode.Contour.front()).
-                            // that point is sadly slightly outisde of the layer A, so no link is detected, eventhough they are overlaping "completely"
-                            Polygon contour_poly(ClipperZUtils::from_zpath(polynode.Contour));
-                            BoundingBox contour_aabb{contour_poly.points};
-                            for (int l = int(m_above.lslices_ex.size()) - 1; l >= 0; --l) {
-                                LayerSlice &lslice = m_above.lslices_ex[l];
-                                // it is potentially slow, but should be executed rarely
-                                if (contour_aabb.overlap(lslice.bbox) && !intersection(Polygons{contour_poly}, m_above.lslices[l]).empty()) {
-                                    found = true;
-                                    j     = l;
-                                    assert(i >= 0 && i < m_below.lslices_ex.size());
-                                    assert(j >= 0 && j < m_above.lslices_ex.size());
-                                    break;
-                                }
-                            }
-                        }
+                if (j < 0) {
+                    if (i < 0) {
+                        // this->find_top_bottom_contour_ids_approx() shoudl have made sure this does not happen.
+                        assert(false);
                     } else {
-                        // Index of an island above. Look-it up in the island below.
-                        assert(j < m_offset_end);
-                        j -= m_offset_above;
-                        for (int l = int(m_below.lslices_ex.size()) - 1; l >= 0; -- l) {
-                            LayerSlice &lslice = m_below.lslices_ex[l];
-                            if (lslice.bbox.contains(pt) && m_below.lslices[l].contains(pt)) {
-                                found = true;
-                                i = l;
-                                assert(i >= 0 && i < m_below.lslices_ex.size());
-                                assert(j >= 0 && j < m_above.lslices_ex.size());
-                                break;
-                            }
-                        }
-                        //FIXME remove the following block one day, it should not be needed.
-                        // The following shall not happen now as the source expolygons are being shrunk a bit before intersecting,
-                        // thus each point of each intersection polygon should fit completely inside one of the original (unshrunk) expolygons.
-                        if (!found) { // Explanation for aditional check is above.
-                            Polygon contour_poly(ClipperZUtils::from_zpath(polynode.Contour));
-                            BoundingBox contour_aabb{contour_poly.points};
-                            for (int l = int(m_below.lslices_ex.size()) - 1; l >= 0; --l) {
-                                LayerSlice &lslice = m_below.lslices_ex[l];
-                                if (contour_aabb.overlap(lslice.bbox) && !intersection(Polygons{contour_poly}, m_below.lslices[l]).empty()) {
-                                    found = true;
-                                    i     = l;
-                                    assert(i >= 0 && i < m_below.lslices_ex.size());
-                                    assert(j >= 0 && j < m_above.lslices_ex.size());
-                                    break;
-                                }
-                            }
-                        }
+                        assert(i >= m_offset_below && i < m_offset_above);
+                        i -= m_offset_below;
+                        j = this->find_other_contour_costly(polynode, m_above, j == -2);
+                        found = j >= 0;
                     }
+                } else if (i < 0) {
+                    assert(j >= m_offset_above && j < m_offset_end);
+                    j -= m_offset_above;
+                    i = this->find_other_contour_costly(polynode, m_below, i == -2);
+                    found = i >= 0;
                 } else {
                     assert(assert_intersection_valid(i, j));
                     i -= m_offset_below;
@@ -329,6 +283,187 @@ static void connect_layer_slices(
         }
 
     private:
+        // Find the indices of the contour below & above for an expolygon created as an intersection of two expolygons, one below, the other above.
+        // Returns -1 if there is no point on the intersection refering bottom resp. top source expolygon.
+        // Returns -2 if the intersection refers to multiple source expolygons on bottom resp. top layers.
+        std::pair<int32_t, int32_t> find_top_bottom_contour_ids_strict(const ClipperLib_Z::PolyNode &polynode) const
+        {
+            // If there is an intersection point, it should indicate which contours (one from layer below, the other from layer above) intersect.
+            // Otherwise the contour is fully inside another contour.
+            int32_t i = -1, j = -1;
+            auto process_i = [&i, &j](coord_t k) {
+                if (i == -1)
+                    i = k;
+                else if (i >= 0) {
+                    if (i != k) {
+                        // Error: Intersection contour contains points of two or more source bottom contours.
+                        i = -2;
+                        if (j == -2)
+                            // break
+                            return true;
+                    }
+                } else
+                    assert(i == -2);
+                return false;
+            };
+            auto process_j = [&i, &j](coord_t k) {
+                if (j == -1)
+                    j = k;
+                else if (j >= 0) {
+                    if (j != k) {
+                        // Error: Intersection contour contains points of two or more source top contours.
+                        j = -2;
+                        if (i == -2)
+                            // break
+                            return true;
+                    }
+                } else
+                    assert(j == -2);
+                return false;
+            };
+            for (int icontour = 0; icontour <= polynode.ChildCount(); ++ icontour) {
+                const ClipperLib_Z::Path &contour = icontour == 0 ? polynode.Contour : polynode.Childs[icontour - 1]->Contour;
+                if (contour.size() >= 3) {
+                    for (const ClipperLib_Z::IntPoint &pt : contour)
+                        if (coord_t k = pt.z(); k < 0) {
+                            const auto &intersection = m_intersections[-k - 1];
+                            assert(intersection.first <= intersection.second);
+                            if (intersection.first < m_offset_above ? process_i(intersection.first) : process_j(intersection.first))
+                                goto end;
+                            if (intersection.second < m_offset_above ? process_i(intersection.second) : process_j(intersection.second))
+                                goto end;
+                        } else if (k < m_offset_above ? process_i(k) : process_j(k))
+                            goto end;
+                }
+            }
+        end:
+            return { i, j };
+        }
+
+        // Find the indices of the contour below & above for an expolygon created as an intersection of two expolygons, one below, the other above.
+        // This variant expects that the source expolygon assingment is not unique, it counts the majority.
+        // Returns -1 if there is no point on the intersection refering bottom resp. top source expolygon.
+        // Returns -2 if the intersection refers to multiple source expolygons on bottom resp. top layers.
+        std::pair<int32_t, int32_t> find_top_bottom_contour_ids_approx(const ClipperLib_Z::PolyNode &polynode) const
+        {
+            // 1) Collect histogram of contour references.
+            struct HistoEl {
+                int32_t id;
+                int32_t count;
+            };
+            std::vector<HistoEl> histogram;
+            {
+                auto increment_counter = [&histogram](const int32_t i) {
+                    auto it = std::lower_bound(histogram.begin(), histogram.end(), i, [](auto l, auto r){ return l.id < r; });
+                    if (it == histogram.end() || it->id != i)
+                        histogram.insert(it, HistoEl{ i, int32_t(1) });
+                    else
+                        ++ it->count;
+                };
+                for (int icontour = 0; icontour <= polynode.ChildCount(); ++ icontour) {
+                    const ClipperLib_Z::Path &contour = icontour == 0 ? polynode.Contour : polynode.Childs[icontour - 1]->Contour;
+                    if (contour.size() >= 3) {
+                        for (const ClipperLib_Z::IntPoint &pt : contour)
+                            if (coord_t k = pt.z(); k < 0) {
+                                const auto &intersection = m_intersections[-k - 1];
+                                assert(intersection.first <= intersection.second);
+                                increment_counter(intersection.first);
+                                increment_counter(intersection.second);
+                            } else
+                                increment_counter(k);
+                    }
+                }
+                assert(! histogram.empty());
+            }
+            int32_t i = -1;
+            int32_t j = -1;
+            if (! histogram.empty()) {
+                // 2) Split the histogram to bottom / top.
+                auto mid          = std::upper_bound(histogram.begin(), histogram.end(), m_offset_above, [](auto l, auto r){ return l < r.id; });
+                // 3) Sort the bottom / top parts separately.
+                auto bottom_begin = histogram.begin();
+                auto bottom_end   = mid;
+                auto top_begin    = mid;
+                auto top_end      = histogram.end();
+                std::sort(bottom_begin, bottom_end, [](auto l, auto r) { return l.count > r.count; });
+                std::sort(top_begin,    top_end,    [](auto l, auto r) { return l.count > r.count; });
+                double i_quality = 0;
+                double j_quality = 0;
+                if (bottom_begin != bottom_end) {
+                    i = bottom_begin->id;
+                    i_quality = std::next(bottom_begin) == bottom_end ? std::numeric_limits<double>::max() : double(bottom_begin->count) / std::next(bottom_begin)->count;
+                }
+                if (top_begin != top_end) {
+                    j = top_begin->id;
+                    j_quality = std::next(top_begin) == top_end ? std::numeric_limits<double>::max() : double(top_begin->count) / std::next(top_begin)->count;
+                }
+                // Expected to be called only if there are duplicate references to be resolved by the histogram.
+                assert(i >= 0 || j >= 0);
+                assert(i_quality < std::numeric_limits<double>::max() || j_quality < std::numeric_limits<double>::max());
+                if (i >= 0 && i_quality < j_quality) {
+                    // Force the caller to resolve the bottom references the costly but robust way.
+                    assert(j >= 0);
+                    // Twice the number of references for the best contour.
+                    assert(j_quality >= 2.);
+                    i = -2;
+                } else if (j >= 0) {
+                    // Force the caller to resolve the top reference the costly but robust way.
+                    assert(i >= 0);
+                    // Twice the number of references for the best contour.
+                    assert(i_quality >= 2.);
+                    j = -2;
+                }
+
+            }
+            return { i, j };
+        }
+
+        static int32_t find_other_contour_costly(const ClipperLib_Z::PolyNode &polynode, const Layer &other_layer, bool other_has_duplicates)
+        {
+            if (! other_has_duplicates) {
+                // The contour below is likely completely inside another contour above. Look-it up in the island above.
+                Point pt(polynode.Contour.front().x(), polynode.Contour.front().y());
+                for (int i = int(other_layer.lslices_ex.size()) - 1; i >= 0; -- i)
+                    if (other_layer.lslices_ex[i].bbox.contains(pt) && other_layer.lslices[i].contains(pt))
+                        return i;
+                // The following shall not happen now as the source expolygons are being shrunk a bit before intersecting,
+                // thus each point of each intersection polygon should fit completely inside one of the original (unshrunk) expolygons.
+                assert(false);
+            }
+            // The comment below may not be valid anymore, see the comment above. However the code is used in case the polynode contains multiple references 
+            // to other_layer expolygons, thus the references are not unique.
+            //
+            // The check above might sometimes fail when the polygons overlap only on points, which causes the clipper to detect no intersection.
+            // The problem happens rarely, mostly on simple polygons (in terms of number of points), but regardless of size!
+            // example of failing link on two layers, each with single polygon without holes.
+            // layer A = Polygon{(-24931238,-11153865),(-22504249,-8726874),(-22504249,11477151),(-23261469,12235585),(-23752371,12727276),(-25002495,12727276),(-27502745,10227026),(-27502745,-12727274),(-26504645,-12727274)}
+            // layer B = Polygon{(-24877897,-11100524),(-22504249,-8726874),(-22504249,11477151),(-23244827,12218916),(-23752371,12727276),(-25002495,12727276),(-27502745,10227026),(-27502745,-12727274),(-26504645,-12727274)}
+            // note that first point is not identical, and the check above picks (-24877897,-11100524) as the first contour point (polynode.Contour.front()).
+            // that point is sadly slightly outisde of the layer A, so no link is detected, eventhough they are overlaping "completely"
+            Polygons contour_poly{ Polygon{ClipperZUtils::from_zpath(polynode.Contour)} };
+            BoundingBox contour_aabb{contour_poly.front().points};
+            int32_t i_largest = -1;
+            double  a_largest = 0;
+            for (int i = int(other_layer.lslices_ex.size()) - 1; i >= 0; -- i)
+                if (contour_aabb.overlap(other_layer.lslices_ex[i].bbox))
+                    // it is potentially slow, but should be executed rarely
+                    if (Polygons overlap = intersection(contour_poly, other_layer.lslices[i]); ! overlap.empty())
+                        if (other_has_duplicates) {
+                            // Find the contour with the largest overlap. It is expected that the other overlap will be very small.
+                            double a = area(overlap);
+                            if (a > a_largest) {
+                                a_largest = a;
+                                i_largest = i;
+                            }
+                        } else {
+                            // Most likely there is just one contour that overlaps, however it is not guaranteed.
+                            i_largest = i;
+                            break;
+                        }
+            assert(i_largest >= 0);
+            return i_largest;
+        }
+
         const std::vector<std::pair<coord_t, coord_t>> &m_intersections;
         Layer                                          &m_below;
         Layer                                          &m_above;
diff --git a/src/libslic3r/TriangleMeshSlicer.cpp b/src/libslic3r/TriangleMeshSlicer.cpp
index 329c1c4ca3..460cd901e9 100644
--- a/src/libslic3r/TriangleMeshSlicer.cpp
+++ b/src/libslic3r/TriangleMeshSlicer.cpp
@@ -1911,6 +1911,16 @@ std::vector<ExPolygons> slice_mesh_ex(
                     this_mode == MeshSlicingParams::SlicingMode::EvenOdd ? ClipperLib::pftEvenOdd : 
                     this_mode == MeshSlicingParams::SlicingMode::PositiveLargestContour ? ClipperLib::pftPositive : ClipperLib::pftNonZero,
                     &expolygons);
+
+#if 0
+//#ifndef _NDEBUG
+                // Test whether the expolygons in a single layer overlap.
+                for (size_t i = 0; i < expolygons.size(); ++ i)
+                    for (size_t j = i + 1; j < expolygons.size(); ++ j) {
+                        Polygons overlap = intersection(expolygons[i], expolygons[j]);
+                        assert(overlap.empty());
+                    }
+#endif
 #if 0
 //#ifndef _NDEBUG
                 for (const ExPolygon &ex : expolygons) {
diff --git a/src/slic3r/GUI/GCodeViewer.cpp b/src/slic3r/GUI/GCodeViewer.cpp
index 36ac85df94..bd4653ab8f 100644
--- a/src/slic3r/GUI/GCodeViewer.cpp
+++ b/src/slic3r/GUI/GCodeViewer.cpp
@@ -697,7 +697,9 @@ void GCodeViewer::init()
             buffer.render_primitive_type = TBuffer::ERenderPrimitiveType::Line;
             buffer.vertices.format = VBuffer::EFormat::Position;
 #if ENABLE_GL_CORE_PROFILE
-            buffer.shader = OpenGLManager::get_gl_info().is_core_profile() ? "dashed_thick_lines" : "flat";
+            // on MAC using the geometry shader of dashed_thick_lines is too slow
+            buffer.shader = "flat";
+//            buffer.shader = OpenGLManager::get_gl_info().is_core_profile() ? "dashed_thick_lines" : "flat";
 #else
             buffer.shader = "flat";
 #endif // ENABLE_GL_CORE_PROFILE
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoSlaBase.cpp b/src/slic3r/GUI/Gizmos/GLGizmoSlaBase.cpp
index 2e76ebc965..0688ca5b2b 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoSlaBase.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoSlaBase.cpp
@@ -59,7 +59,7 @@ void GLGizmoSlaBase::update_volumes()
         if (last_comp_step == slaposCount)
             last_comp_step = -1;
 
-        m_input_enabled = last_comp_step >= m_min_sla_print_object_step;
+        m_input_enabled = last_comp_step >= m_min_sla_print_object_step || po->model_object()->sla_points_status == sla::PointsStatus::UserModified;
 
         const int object_idx   = m_parent.get_selection().get_object_idx();
         const int instance_idx = m_parent.get_selection().get_instance_idx();
diff --git a/src/slic3r/Utils/EmbossStyleManager.cpp b/src/slic3r/Utils/EmbossStyleManager.cpp
index d82bbcb7b7..2653e5c1df 100644
--- a/src/slic3r/Utils/EmbossStyleManager.cpp
+++ b/src/slic3r/Utils/EmbossStyleManager.cpp
@@ -451,8 +451,7 @@ ImFont *StyleManager::create_imgui_font(const std::string &text, double scale)
     // TODO: start using merge mode
     //font_config.MergeMode = true;
 
-    const auto  &cn = font_prop.collection_number;
-    unsigned int font_index = (cn.has_value()) ? *cn : 0;
+    unsigned int font_index = font_prop.collection_number.value_or(0);
     const auto  &font_info  = font_file.infos[font_index];
     if (font_prop.char_gap.has_value()) {
         float coef = font_size / (double) font_info.unit_per_em;