I'm having a real hard time figuring out how I would catch/hit a transmitter on something during a dive (if I had one).
Would be very interesting to see how OP thinks a transmitter is positioned if he believes that is a risk big enough not to use one.
I have my transmitter on a short hose, which I bend down and tie with a bungee loop to a regulator hose. So the transmitter is always tucked between the tank and the wing. In that position, it's practically impossible for the AI transmitter to be bumped. The tank valve or my head will protect it