This is also something that I’m looking forward to see how it works. I know EntityManager has a method to do it (MoveEntitiesFrom), which should be used when you have entities ready to enter in the “view” world, so you move from one world to another.
[mention|bTdNHCnXGjDOtP9jfwX0YA==] wrote a gist to show how worlds can be used to separate systems. You can see it here. Also read his post about this gist here .