Looks suspiciously a lot like the work profile with Island...
What's Graphene's standpoint on this?

(It is already out in Beta 2)

Have you tested it? My impression was that it was a separate thing to a work profile. Otherwise they would have mentioned it replacing work profiles.

If it could work without the need of Play Services, it would be amazing. You would no longer need to rely on a 3rd party app like Shelter or Insular if I understand correctly. I assume it is intertwined with Play services though, does anybody know? I don't know much about this potential feature but find it interesting...