basically it means you can block of parts of the map (good for infection), you could put a crate in the lift and then put a reciever node ontop to keep it in place, it'l mean they can't use the lift.
to stop the towers on sandbox, glitch yourself out of the skybubble (needs another person, and a turret) then put double walls over the eyes of the towers, this stops them for hitting you, they still shoot but there is no flashing and you don't die. Now you have a desert with almsot limitless opourtunities.