Not sure if it has been fixed, but problem with lookForAtArea(WHAT,..) is that it returns only the one item of the same type on a given cell - at least it used to.
This obviously can't work for structures. One would think that it would be OK for terrain, but I've seen map tiles that have a wall and a swamp on the same tile - lookForAtArea('terrain',...) returns one of them, so you'd treat the cell walkable, while it's not, or the other way aroun.