I would just make it a penalty for a coach to yell, use hand signs or otherwise try to suggest the ref should make a call against the opposing wrestler. If they want to question a call, that is what the brick is for. If there is a scoring issue, go to the head table. But if the coach is putting up a fist to suggest stalling should be called, that would be unsportsmanlike conduct on the coach and a team point. They are showing disrespect to the ref and setting a bad example of sportsmanship to their team.