Still. Two walls, you become nearly impervious to anything, four walls, nothing ever can touch you short of making some kind of bomb and blowing them out. Four wall. You could make four walls easily, with little damage or time wasted on your part. On the other hand, if someone does their little hole, you need to get chemistry to make you exploding grenades, or get science to make a plasma bomb with a low enough yield to not rip the station in two. If that isn't unbalanced, nothing in this game is. Theres also all time times Ive seen cultists hear that the ERT's been called, and bumrushed to arrivals as they could seal up any and every way the ERT could get in without breaching the station. Id be find with them, as long as there was something to stop them from placing another wall directly adjacent to another one, that'd stop any and all possible abuse.