I think you're assuming behavior on the part of an OOA diver that may not be as predictable as you think. The most likely event IME with an OOA diver is that they'll simply yank the 2nd stage right out of your mouth; it's happened twice to me. (Interestingly, both times by semi-panicked DM candidates in drills....kind of scary when you think about it)
I also think it's a good idea to have a look at how stage bottles are commonly rigged; the technical divers have figured this sort of thing out pretty well. On the ultra-rare occasion that I carry a pony, I rig the hose like a stage hose; secured along the side of the tank with inner tube bands. That way you rout the hose down and back up the tank so the 2nd stage is right near the valve, and a tug pulls it free. If you're really planning on handing this bottle off to a OOA diver, you might find that a longer hose is much more convenient.