If it helps anyone here, these people on Steam have had some success with Proton:

https://steamcommunity.com/app/1224290/discussions/0/3012305144379724393/

I was one of the beta-testers for Alvora Tactics, so I've had a bit of time to try it out!

If you're wondering how it compares with Voidspire Tactics, the earlier related game:

• The tactics combat and class system is much more refined. There are more race and class options, and they are better balanced.
• There are still plenty of surprises (including a big-secret zone), though the game is definitely more focused on the combat than on the exploration.
• Levels are procedurally-generated, which leads to a few emptier rooms, but the replayability value is higher. As a person who's generally tired of procgen games, I thought this one used it well to spread things out rather than to waste time.
• The game is shorter -- maybe half the time of Voidspire for one run-through -- but I was much more inclined to try another run when I got to the end.

Overall: it is a good time and you should check it out!