Strange. It runs even on Ultras for me on Debian 10 with updated Vulkan Loader, but freezes solid with 10-15 minutes. If you restart it, it works fine for another 10-15 minutes, eh-eh-eh... Glad it does at all. Threadripper 1920X, 64 gb RAM, "impossible to obtain" RTX card, official Nvidia beta driver 455.46.02.
You're using Proton 5.0-10 which has a massively outdated version of vkd3d-proton.
Use proton 5.13-4, 5.0-10 will not run the game

proton 5.13-4x1 2020-12proton 5.0-10x2 2020-12
The CDPR Launcher works fine then CP2077 fails to launch
Steam
Proton 5.0-10
Nvidia 1080ti
Ubuntu 20.04
Proton log:
https://gist.github.com/ryanwalder/bb9bdd0ed226a5f25a4a8a0ca7d10b3e