Proton 6.15 GE 2 (https://github.com/GloriousEggroll/proton-ge-custom)

Performance is very inconsistent, on launch it may run perfectly fine but after some time it degrades significantly (not always?). Restart of the game seems to help only partially. However these issues seem to only be present in the multiplayer of the game as I did not experience any significant performance drops in singleplayer. I would consider multiplayer to still be somewhat playable at around 25-30 fps on lowest graphical settings.