Well if I am incorrect, why are they not used in every other dirt type motorsports? Worse yet is how many just completely fail, right out of the box or six months down the road. I see the reason in indoor and all the spectators in outdoors in the World rounds. As far as the throttle sticking wide open , a proper pair of bar ends is a device that does that job well.
I have seen more people lose events due to this device than any good it does.