What About Bonea?

[vincentric]

Bob was shown being able to cross over into the Never Never in Ghost Story, he doesn’t need to go back, unlike Evil Bob, because he has a Sanctum

I've never doubted that Bob could reach the Never Never, I just doubt that he can manifest a body for himself. So far only powerful insane ghosts(Harry included himself there) have shown this ability.

[Conspiracy Theorist]

Bob knows how to kill an immortal, that’s why he stays out of Mab’s way.