Which ones have you found incompatible?

I haven’t found one which won’t work for me. At the very least, if you run say Steam on your Linux desktop, you can download the offline backup on your games files and then:

• Install ProtonTricks
• Download GE-Proton (whatever the latest is!)
• Go to your offline backup folder with the game files, and add the executable file to Steam (right-click, add to Steam)
• From within Steam, go to properties and then compatibility, and choose your GE-Proton
• Run the installer (I recommend making it install to: /home /deck /Games
• Remove the setup from Steam
• Once the game is installed wherever you wanted it to go to (I recommend making a folder in your ‘home’ folder called ‘Games’), find the game’s executable file ‘ArtOfRally.exe’ for example, and do the same: right-click on it, add to Steam, then again in properties choose GE
• Play the game. 9/10 times you’ll find the dependencies covered by GE-Proton, in the rare case it isn’t, you can use something like Lutris to do this!

But…again I haven’t had any issues. If you can think of a game title you haven’t been able to run by using Heroic Games Launcher, then let me know, and if I have it I will troubleshoot it for you! More than happy to help :)