So, it was still freezing, but I've managed to have a litttle bit more luck running it?
Here's a player.log from a sucessful run:
vs a current unsuccessful one:
https://pastebin.com/n0quF2TC
The difference really seems to be in that VK_ERROR_DEVICE_LOST line, and I can't quite figure out what's caused that. Tried glancing at a couple things, like alt-tabbing from the game or making sure the HMD was not in sleep mode, but no luck.
This seems the right time to note that I'm using nvidia-driver-440 on my 980 Ti, specifically apt pulls the version as 440.82+really.440.64-0ubuntu6 amd64. Juuuust in case that helps.