I got it to work perfectly from this guide: https://piped.video/watch?v=_PLEm1v9bzw Works really well high fps and all. Something I dont think the guide mentions is updating the battle eye runtime using the one from steam.

I figured it out.

I added the Ubisoft Connect installer as a non Steam game, installed it with GE-Proton9-4, and then switched the shortcut to the location of "UbisoftConnect.exe".

Then, in the launch options, I put:

PROTON_BATTLEYE_RUNTIME="$HOME/.steam/steam/steamapps/common/Proton BattlEye Runtime" %command% uplay://launch/15657

And make sure the Proton BattlEye runtime is installed through Steam.

I played multiple full matches in a row like this without any issues.

Edit: Oh I almost forgot, you also need to get a copy of pdh.dll and put it in the game's directory.

Tried a couple times - installing via lutris, or proton, played with some winetricks etc. Eventually the launcher worked, then more tweaks for the game to load. But then gave up once it crashed to desktop loading the game every time.

Its a shame, reasonably fun game overall.

Haven't tried yet, but I've seen some people on YT claiming to have done so... If you try it out let me know if you succeed!