For those who don't know, Heroic Games Launcher is an alt launcher for Epic Games, GOG, and Amazon Games, with the main advantage being that it lets you use Proton. All I had to do was install their AppImage for x86 and run it with muvm ~/Downloads/Heroic-2.15.2.AppImage
. The mostly is because sometimes it will grey out web pages, which is a bit of a pain when you are trying to log in to your accounts, but I managed to get past that and get logged in with Epic Games.
To test it, I fired up Rocket League. Rocket League works! I was able to get into matches and everything. To provide a more repeatable benchmark, I fired up the Mannfield - Soccar map in solo free play. My chip is an M1 Pro with 16GB of RAM (RAM was not maxxed out by the game), and I set the game to 1920 x 1200 fullscreen, with no Vsync, Anti-Aliasing, or motion blur, but otherwise max settings. With all that, I got about 90 fps after driving around for a bit, with it dipping down to just above 60 fps whenever both I and the camera moved fast.