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.
While usually true, this isn’t always the case. Some games have differences in code between the versions released. Modders especially will butt up against this from time to time.
As a pirate, running on steamdeck, using proton… Mods aren't usually where I'm going. Haha.