temps: You're saying I can play Cyberpunk in Steam's Proton technology even if I bought my Cyberpunk game from GOG? If so, that would pretty much solve my problem.
It does work. Here's how:
1. Run these commands one line at a time in a terminal (If you use Ubuntu or similar, press Ctrl+Alt+T):
sudo add-apt-repository multiverse sudo apt update && sudo apt upgrade sudo apt install steam 2. Open Steam
3. Log in
4. Steam > Settings > Steam Play and turn on "Enable Steam Play"
5. If Proton is all you want to use, do this, but if you want to use different versions, or enable Wine for some games, skip this: Enable for all titles.
6. Close Settings and restart Steam
7. Go to Tools in Library and install the latest Proton
Add Cyberpunk 2077:
8. From the Games menu choose "Add a Non-Steam Game to My Library"
9. Browse to and select Cyberpunk 2077 (You might need to switch the view to All Files to see .exe files.)
10. If you skipped 5, then right-click Cyberpunk 2077 once it's in your library and choose "Properties"
11. Select "Force the use of a specific Steam Play compatibility tool" to use the Proton instead of the system default Wine. Select the desired Proton version from the drop down menu.