If you are concerned enough about the possibility to raise it here, I would agree that you should remove the transmitter, put a port plug in the first stage port, and a cover of something over the male transmitter port. I do not do that for airline travel myself - I leave the transmitter attached to the regulator first stage - but there is no real harm in being safer than sorrier, unless you crossthread the transmitter when re-attaching it, or fail to tighten it properly (too little or too much), or don't secure the transmitter and it falls out / gets lost, etc.
