Have you tried Lutris + GE-Proton + umu?
Edit>> Simply: Install Lutris, install Protonplus, install GE-Proton9-15 (or latest) with Protonplus, install game within Lutris. Configure the Runner for the game to use GE-Proton and then run the game (which Lutris will launch the game using umu).
I’ve been running WoW this way for many months with no issues and no fps problems.
Edit2>> You may be able to tell Lutris where to look for the game, but I would advise installing fresh on your ext4 or btrfs or whatever Linux drive you have.
Also, if it helps get you away from Windows, I’ve been running games this way since April, and finally dumped Windows for good. The only games I can’t play are those with unsupported anti-cheat (which I don’t play anyway so it doesn’t affect me).
Edit3>> And in case you were wondering, I’m running Garuda Linux (Garuda KDE Dr460nized version but I changed the theme).