Things GMS may (not) get

and fix the party play exp; it's dividing by the percent it should be boosting it by. Or maybe it's just the new area's party play thats messed up. I cant get a SH/HoH party to test that one.

I've no idea what you're trying to say here.
Party Play bonus exp is not dividing anything. However, it only applies to the base exp, not any other bonuses (HS, 2x, etc), so it's a lot less than we're used to seeing. Also, in Perion it's only 20%, as opposed to the 50% of previous Party Play areas.