Has anyone tried using the Black Books as a way to escape tricky situations? Since (as far as I know) we don't immediately encounter enemies when entering Apocrypha, we could use the Black Books when we are in trouble and heal up using spells, reassess our strategy then go back to Tamriel. Perhaps we could even purposely throw some stuff in Apocrypha for emergency use when we port there.
I believe one of the new books told of how Miraak was almost killed by the 'Guardian' or something but Hermaeus Mora whisked him away, maybe now we can do that in this way?

One problem I foresee is that the Black Book takes some time to transfer you to Apocrypha so we might still get killed when the tentacles are pulling us in.