diff --git a/plugins/USBPrinting/USBPrinterOutputDeviceManager.py b/plugins/USBPrinting/USBPrinterOutputDeviceManager.py
index 5009ba69bb..760b1b1564 100644
--- a/plugins/USBPrinting/USBPrinterOutputDeviceManager.py
+++ b/plugins/USBPrinting/USBPrinterOutputDeviceManager.py
@@ -1,7 +1,7 @@
 # Copyright (c) 2015 Ultimaker B.V.
 # Cura is released under the terms of the AGPLv3 or higher.
 
-from UM.Signal import Signal, SignalEmitter
+from UM.Signal import Signal, signalemitter
 from . import USBPrinterOutputDevice
 from UM.Application import Application
 from UM.Resources import Resources
@@ -28,7 +28,8 @@ i18n_catalog = i18nCatalog("cura")
 
 
 ##  Manager class that ensures that a usbPrinteroutput device is created for every connected USB printer.
-class USBPrinterOutputDeviceManager(QObject, SignalEmitter, OutputDevicePlugin, Extension):
+@signalemitter
+class USBPrinterOutputDeviceManager(QObject, OutputDevicePlugin, Extension):
     def __init__(self, parent = None):
         super().__init__(parent = parent)
         self._serial_port_list = []
diff --git a/resources/definitions/fdmprinter.def.json b/resources/definitions/fdmprinter.def.json
index 911d81031f..8cec9cfeb4 100644
--- a/resources/definitions/fdmprinter.def.json
+++ b/resources/definitions/fdmprinter.def.json
@@ -2497,7 +2497,7 @@
                     "description": "The speed at which the raft is printed.",
                     "unit": "mm/s",
                     "type": "float",
-                    "default_value": 30,
+                    "default_value": 20,
                     "minimum_value": "0.1",
                     "maximum_value": "299792458000",
                     "maximum_value_warning": "200",
@@ -2513,7 +2513,7 @@
                             "description": "The speed at which the top raft layers are printed. These should be printed a bit slower, so that the nozzle can slowly smooth out adjacent surface lines.",
                             "unit": "mm/s",
                             "type": "float",
-                            "default_value": 30,
+                            "default_value": 20,
                             "minimum_value": "0.1",
                             "maximum_value": "299792458000",
                             "maximum_value_warning": "100",
@@ -2528,12 +2528,12 @@
                             "description": "The speed at which the middle raft layer is printed. This should be printed quite slowly, as the volume of material coming out of the nozzle is quite high.",
                             "unit": "mm/s",
                             "type": "float",
-                            "default_value": 15,
+                            "default_value": 20,
                             "minimum_value": "0.1",
                             "maximum_value": "299792458000",
                             "maximum_value_warning": "150",
                             "enabled": "adhesion_type == \"raft\"",
-                            "value": "0.5 * raft_speed",
+                            "value": "raft_speed",
                             "settable_per_mesh": false,
                             "settable_per_extruder": true
                         },
@@ -2548,7 +2548,7 @@
                             "maximum_value": "299792458000",
                             "maximum_value_warning": "200",
                             "enabled": "adhesion_type == \"raft\"",
-                            "value": "0.5 * raft_speed",
+                            "value": "0.75 * raft_speed",
                             "settable_per_mesh": false,
                             "settable_per_extruder": true
                         }
@@ -2742,9 +2742,7 @@
                     "label": "Platform Adhesion Extruder",
                     "description": "The extruder train to use for printing the skirt/brim/raft. This is used in multi-extrusion.",
                     "type": "extruder",
-                    "default_value": 0,
-                    "minimum_value": "0",
-                    "maximum_value": "machine_extruder_count - 1",
+                    "default_value": "0",
                     "settable_per_mesh": false,
                     "settable_per_extruder": false
                 },
@@ -2753,9 +2751,7 @@
                     "label": "Support Extruder",
                     "description": "The extruder train to use for printing the support. This is used in multi-extrusion.",
                     "type": "extruder",
-                    "default_value": 0,
-                    "minimum_value": "0",
-                    "maximum_value": "machine_extruder_count - 1",
+                    "default_value": "0",
                     "enabled": "support_enable",
                     "settable_per_mesh": false,
                     "settable_per_extruder": false,
@@ -2765,10 +2761,8 @@
                             "label": "Support Infill Extruder",
                             "description": "The extruder train to use for printing the infill of the support. This is used in multi-extrusion.",
                             "type": "extruder",
-                            "default_value": 0,
+                            "default_value": "0",
                             "value": "support_extruder_nr",
-                            "minimum_value": "0",
-                            "maximum_value": "machine_extruder_count - 1",
                             "enabled": "support_enable",
                             "settable_per_mesh": false,
                             "settable_per_extruder": false
@@ -2778,10 +2772,8 @@
                             "label": "First Layer Support Extruder",
                             "description": "The extruder train to use for printing the first layer of support infill. This is used in multi-extrusion.",
                             "type": "extruder",
-                            "default_value": 0,
+                            "default_value": "0",
                             "value": "support_extruder_nr",
-                            "minimum_value": "0",
-                            "maximum_value": "machine_extruder_count - 1",
                             "enabled": "support_enable",
                             "settable_per_mesh": false,
                             "settable_per_extruder": false
@@ -2791,10 +2783,8 @@
                             "label": "Support Roof Extruder",
                             "description": "The extruder train to use for printing the roof of the support. This is used in multi-extrusion.",
                             "type": "extruder",
-                            "default_value": 0,
+                            "default_value": "0",
                             "value": "support_extruder_nr",
-                            "minimum_value": "0",
-                            "maximum_value": "machine_extruder_count - 1",
                             "enabled": "support_enable",
                             "settable_per_mesh": false,
                             "settable_per_extruder": false