> after booting my VM KDE just flashed because my external GPU was gone but everything went back working without a need for relogin.

What GPU are you using and how did you configure this, if you don't mind me asking? On my end I just can't unload the driver for it if I let KDE start with the external GPU available.

A Sapphire Radeon 9070 as the external GPU and a Ryzen 7 7600 as the integrated GPU. But I don't recommend this particular model for the 9070 if you want to do VFIO, it has the infamous reset bug so after booting the VM once I can't use the external GPU anymore unless I restart the machine. Also I never got the VFIO completely working, I could pass the GPU to the VM but the VM could not find the GPU (e.g., the AMD drivers said "no GPU found" while running the installer).

Actually, now that I think about this could be that my system is set to autologin (I am using Jovian-NixOS to get a almost SteamOS experience), so maybe this is not KDE being smart and could just be that it crashed and the system automatically login again. So yes, maybe this doesn't work.