Its been done, its pretty simple actually to drop a fifth wheel with any hitch, other then an Andersen. The fact you haven't seen it happen with a B&W doesn't mean it hasn't happened, and it has been reported on this forum .
All the things we keep reading about problems with the B&W would keep me away from one, their great customer service we keep reading about is not much consolation sitting somewhere trying to get the hitch to release or parts going bad, waiting for them to be shipped.
The one fact about being able to lock the B&W in the open position, makes for a poor design right there along with the other mechanical issues. My previous hitch the Reese signature, same hitch basically as the Reese Elite, could not be kept or locked in the open position, as soon as you back into it, it closed. IMO right there made it a better built ,and designed hitch then the B&W.
One fact remains, all this nonsense ,and mechanical parts are eliminated with the Andersen with its simple design. Being an owner of both types of fifth wheel hitches, I CAN make the argument the Andersen is a better hitch overall then the conventional hitch.