Since proton was updated with non debug d3d11 dlls, the game doesn"t crash anymore when trying to browser on multiplayer, but it doesn't find anything, and quick games doesn't find any games.
With lastest proton 3.16-6, multiplayer works (maybe because of gnutls v3 implementation), game is fully playable.
Confirming that it seems to work flawless with Proton 3.16-6 Beta. Would now make it a whitelist candidate.
edit: Just realized, the abilities show a black box next to description in the overlay, when hovering with the mouse pointer over them. I guess a video should be played here.
But other than that, it's working great!
proton 3.16-6x2 2019-01
Kubuntu 18.04, nvidia 396.51.
It also crashes when trying to view custom games.
Edit: May be related to #112