I've never knocked any of my transmitters off, however I am constantly taking them off the hot-shoe to meter lights, adjust power settings e.t.c. which would be a lot more difficult if were to unscrew them and reattach them every time - I can imagine that a lot of other studio photographers do the same. Additionally, I'd much rather the transmitter came off the hot-shoe when it took a knock than the camera itself taking the impact.
The simple solution is to order two transmitters - that's what I've done. And since you should always have a backup on a paid shoot it serves two purposes. One on the camera another to meter the lights.



