I finally got around to upgrading this (now old) machine from 16.04 -> 17.10 over the last couple days. After fighting with DKMS it's finally booting and working... except the screen keeps flashing.
Why am I facing this reportedly fixed bug?
I managed to fix it by going into the NVidia X Server Settings and turning off this flag:
As soon as I unchecked that, everything was fine.