Having the body control to produce false, seemingly involuntary signals - while suppressing true involuntary signals - implies a level of physical mastery to the extent that you, likely, already possess a substantial advantage in the bout. This is like selling a fake tell in poker while not actually having a tell - even James Bond would tell you that's hard.
You could just sell enough fake tells--produce enough false signals--to throw your opponent off of whatever actual tells you have. I wonder if this is similar in concept to the "drunken" kung fu style.