A big shout out to ElZetta customer service. I snapped my ZRX mount screws and they sent me new rings with no questions or ridicule whatsoever.
My advice is to work your way up and try to stay below max torque. In retrospect, I don't think you need to go anywhere near max torque.
I own an A and a B. IMO,they are the best flashlights in the world!
Thanks!