I was expecting comments on this point, but none was made so far. The current solution allows to reduce the load on the server significantly, can you elaborate why it is such a big problem and why for creative servers in particular?
I understand the reducing load problem as with your Area Attribute solution you save a lot of computations from iterating over all areas as red51 told me a few days back. But is it so bad to iterate over 1000-5000 areas? Java is slow but it is not thaaat slow
I said for creative servers mostly as for PvP servers destroying other people's stuff is part of the game so even if they use some AP settings most of it should be fair game to destroy from inside or outside the area.
Now it is a big problem as when I give a player an area 200x200 blocks they expect it to not be able to be griefed in its whole not have a small 2-3 block perimeter where it can be dug or their builds destroyed Also when I want to protect roads or portals I want to be able to have small areas around them to allow for the rest of the space for player areas but such small areas with the reach-in issue would lead to all our roads and portals destroyed by a griefer
Edit PS: our server is quite big and we constantly only have about 2000 areas as we remove old areas after 30-40 days of inactivity