Not sure if this will work as I don't have a GPU that works with gamescope but steamos-session-select gamescopesteamos-session-select gamescope might work for changing the startup to gamescope when you are in the deck image.
I should have clarified that on Bazzite with KDE, the combo to open system monitor is "meta+esc" becuase this is linux and of course it would be different on the GNOME version lol
Last build of bazzite based on fedora 39 worked. Idk if there was one in fedora 40 that worked. My htpc is stuck for the same reason as you since I have a Polaris card