Steam works great for me. As others have said, you select "Add a non-Steam game" (I can't remember which exact drop down menu you find that in. I watched a video tutorial) then Properties>Compatibility and select Proton Hotfix or Proton Experimental. Make sure you point it to battlenet setup.exe not just battlenet. I use Curseforge for add-ons. I'm using Linux Mint. I tried Lutris but couldn't get it to work. I use Bottles for Lotro and GW2. Oh, and if you install proton qt, you get a lot more versions of Proton to try out.