Theoretically could Billy loop...

like Undead users can if he had somehow kept undead?

so before the end of Loop 100, it was revealed that Billy lost Undead and had to substitute it with Unruin. Billy explicitly stated that Unruin was practically a worse version of Undead due to being unable to loop like Undead can.

Does this mean had Billy kept Undead somehow (even though Andy had stopped viewing Andy as a threat) he could have lived through the destruction of Earth and "looped" like Andy did or no because of Billy's more limited interpretation of Undead