I came across this issue on MBP 16 today w/ 11.0.1 (A variant of rellect's process) Part 1: Mac crashes at login screen, then boots up with Mac's equivalent of BSOD. Once its recovers back to login screen. Press the shutdown icon to shutdown the Mac. Press Cmd+R and power button to go to recovery mode. Then unlock by selecting my user account. Then unlock with my password. Then shutdown, and press power button to boot back up to the login screen. Entered the password and it caused the crash again. Part 2: It recovered back to login screen again. Force shutdown by pressing button until the power goes off. Then press the power button again to boot back up to the login screen. Then entered the password to login normally. Mac's security and privacy has a bunch of popus noting some kernel externs were disabled as they caused bootloop. Disabled all the extensions from loading and everything seems to be back to normal. It is clear that Part 1 didn't work, however, I am not sure if the second part worked because of part 1. I recommend just trying part 2 and if it doesn't help, then try part 1 and then part 2. Hope it helps!