I've been running the vanilla OC from message 1 with the config.plist and Big Sur for over a year now with no problems whatsoever. Updated OC and Big Sur as updates became available all smooth sailing.
Until a couple of weeks ago I routinely updated to 11.6.8. On reboot I got the black screen with the "Your computer restarted because of a problem..." in 5 languages.
Booted my backup Mojave drive, all good.
Reinstalled OC on a usb drive, installed BS 11.6.1 on the internal SSD, installation went fine, first boot "Your computer restarted blah blah..."
Booted Mojave from new usb drive OC, fine.
Tried reinstalling different BS version (11.6.7). Same, installation runs fine, first reboot "Your computer restarted blah blah..."
Disconnected everything on the Mac, reinstalled to different drive and from different sources (usb,sdd) same result.
Tried installing Montery 12.4, installation runs fine, first reboot bang.
In my desperation even tried OCLP 0.4.9 with new installer from usb drive, again installation ran fine, first reboot crash.
I've cleared NVRAM 3 times on most reinstalls, I've tried multiple hw drives, Mojave runs perfectly with or without OC, but for the life of me I can get BS or Monterey to boot.
Totally baffled.