I’ve always appreciated gog releases. I have an account there and installing their games on the steam deck is pretty straight forward from desktop mode. If given the option, use a good old games released game instead of a steamrip. It’ll be better in the long run.
If I installed a GOG games to my linux desktop, can I just copy the install folder to my steamdeck or will I need to run the installer again on the steamdeck?
So far as I know, it would be a proton instance. If you copied that whole thing over you should be fine. Then just add to steam and tell it to use compatibility.