We want to keep it this way so people can still make plugins work for older versions of Cura, like 3.6, where the 'api' field with just a single major version, instead of the 'supported_sdk_versions', which can be either a version-string like '7.6.0' or a list of version strings.
The Cura 4.9 release will have expanded functionality. If you have a plug-in that uses this functionality, marking it as using SDK 7.5.0 will notify older Cura releases that they can't use that plug-in.
Conflicts:
plugins/VersionUpgrade/VersionUpgrade460to462/VersionUpgrade460to462.py -> On master we removed the getCfgVersion function, while we moved the entire plug-in to a different folder in 4.6.
resources/definitions/skriware_2.def.json -> On master we merged a PR that changes more or less all settings, while on 4.6 we doubled the maximum deviation.