In original DK teleporting units was checking reachability of place where they teleport, but in KeeperFX some units can teleport in unreachable places:
Behind closed door(as example enemy vampire teleported into closed room in my dungeon with imps. Or mistresses teleported out of closed room due payday).
On unreachable islands in lava - i had situation when they was stucking on small island(it was mission called Defection of Post Ancient Keeper campaign) after teleportation so i had to control that little idiots
In original DK teleporting units was checking reachability of place where they teleport, but in KeeperFX some units can teleport in unreachable places: