I had a long chat with Mentorn judges about this. I wanted to use chains threaded with piano wire on my wheels to act as a defense. The idea being that if hit by a spinner then they end up wrapped round the bearings and jam the motors. This seems valid to me as you are not and have no intention of immobalising another robot just stopping the weapon.
However if this got caught up in the wheels then you were imobalising the robot.
To many risks of getting disqualified for us.
It would be nice if we could air the idea again as us flippers really do need some form of allowable defense apart from ever thicker amour (boring).
If your going to have rules about entanglement then to balance the equation you need rules limiting kinetic energy imparted by spinners.