A bunch of override files in postmarketos-base-ui-plasma seem to have come from the plasma-mobile ui package, which probably shouldn't be on desktop and bigscreen.
With Plasma 6, a lot of the overrides are now no longer necessary for Plasma Mobile.
Situation with each file:
- 000-gschema.override - This likely was for changing maliit themes and GTK title bar layout for Plasma Mobile, maliit theming was dropped (https://github.com/maliit/keyboard/pull/108), and title bar layout is now handled within Plasma Mobile
- kdeglobals - This was for setting the look-and-feel on Plasma Mobile and default browser, it's now handled within Plasma Mobile envmanager
- kwinrc - These were settings for disabling window decorations and setting the vkbd to maliit, which is now handled in Plasma Mobile envmanager
- kscreenlockerrc - This is to autolock the screen after login (tinydm autologs in), the file was for Plasma Mobile, I don't think we want it for Desktop since SDDM is used there
