Hi tunnel dwellers,
For those attempting to play Underrail in Linux, using Lutris/Wine, I experienced severe stuttering and mouse issues, but was able to get rid of those issues by
switching from WineMono to DotNet/XNA using WineTricks (install program). I also had v-sync disabled, which might have some, but not exhaustive impact, since I also tried switching it off before the other fixes.
So if you're struggling with performance in Linux, you might want to try that.