Thanks for tips. I can't take pic after it hangs. There is around 5 sec delay between.Verbose texts disappear, apple logo shows, then switches to login screen breefly, and then it screen goes black, keyboard is working (caps lock etc). I took the screen shoot last verbose screens. Is there a specific log that will have this information at the time of crash? I have attached OpenCore log file. This is a fresh install of BigSur. So, I didn't personally install any NVIDIA drivers. That said, I posted earlier about keststat in which I see a NVIDIA kext. Comes from Apple I guess.
% kextstat|grep -i -e "nvidia"
Executing: /usr/bin/kmutil showloaded
No variant specified, falling back to release
99 0 0xffffff7f9b8c7000 0x2000 0x2000 com.apple.nvidia.NVDAStartup (16.0.0) B7E8FE3A-5A44-3EA0-9A3B-345B583BFF31 <14 5 3>
Yes, video card wasn't there when i tested. It doesn't make difference either way - both crashes because it's disabled in config.plist.