KDE - changing the way you use Qubes

[unman]

first of all i have a general question about the new template naming in 4.2.1 → fedora-39-xfce/debian-12-xfce - why is the desktop env now specified in the template name?

So that it is clear to users what flavor they are using.

i’m asking because i can no longer start any appvm gui after switch to kde and now wondering whether there has been a major change that prevents the use of kde or its just not longer compatible and perhaps thats why its explicit named xfce?

No change - KDE is usable on 4.2 as before.
There are no KDE templates, but you can start with a basic template and
install all the KDE you want.

after reboot and switch to sddm, no appvm window spawns, but the vm is running without error messages. when i switch back to lightdm everything works as expected… any ideas whats going on?

What vm are you talking about? What appVM window would you expect to
see?

I never presume to speak for the Qubes team.
When I comment in the Forum I speak for myself.