-reapers can't navigate the map properly (can't jump up ladders)
-chainsaw bosses can navigate the map, but they get stuck if they need to get past the doors

em01 20em (spawns in north area, close to one player spawn)
em02 25em (spawns in middle-north area, floor level)
em03 20em (spawns in middle area, top level)
em04 20em (spawns in south area, top level, close to one player spawn)
em05 20em (spawns in middle-south area, floor level)
em06 30em (spawns in middle, floor level)
em09 3em (bosses)