Nvidia Flex however does not work which is somewhat disappointing. Kernel is 4.18 (manjaro), cpu is 4th gen intel i7. I played the game a lot yesterday, it was a great experience. It's possible that some fixes in the nvidia vulkan beta driver (396.54.09) are required for the game to be crash free, but as the game worked fine for mimattr as well, I assume that it probbaly isn't. (May be related to net framework failing to install). I've had no crashes whatsoever, although my inventory and the store did not work at some point, at a later launch while playing I noticed they suddenly worked. The performance is very close to native as we usually see with DXVK, normally it's around 80%. Played with avg 60fps on 980-Ti at 1440p(2k) with settings on ultra. I played a match, got some perk levels, restarted the game and can also confirm that perk progress is saved.
No tweaking around the prefix required, no settings required, it just works. Can confirm this game works for me out of the box, and runs great.