Only solution I can think of would be to have a trench 100-200m away from the border of the map like the one around prison island.
Or tents should be only inserted / saved into the hive database if their X/Y position is within the intended map area. Tents inside the debug plains would therefore only exist until the server isrestarted. [ez-tiger]
P.S.: I don't know if the tents in debug area are wiped after a server restart? Would be nice to know.