I agree with Catherine that in the absence of open minds, new applications for technologies won't move the field forward. I also agree that equipment items are like tools in a toolbox, and there *may* be a very specialized use for something like this - that is, under extremely narrow circumstances.
But for general recreational diving I can see a number of drawbacks to something like this, and one of the first is that if your insta-buddy isn't familiar with it and has some problem, trying to familiarize them with it underwater could get interesting.
I think the drawbacks of many devices designed to respond to sudden emergencies is that the designer never actually experienced any sudden emergencies.
So the designer makes a number of assumptions regarding how sudden emergencies will happen and designs accordingly. Obviously, when the diver practices an "out of air drill" for example, they do so under the same assumptions.
But sudden emergencies have this annoying habit of not proceeding as people assumed they would. You find yourself trying to do about 8 things at once with another diver on the verge of panic, swimming against current and trying to unclip this or untangle that with only one hand because the other hand is holding onto the other diver, dumping gas as you ascend if you can spare a hand to dump it, and now you're trying to do all these tasks while breathing hard off this tiny POS in your mouth, holding it in your teeth, getting wet inhalations because you're sucking wind, streaming bubbles out between your teeth so you can't see, god help you if the hose gets ripped out during the flailex and your teeth lose their grip on the dinky thing, oh yeah.......I think I'm going to run right out and get one this afternoon.
Not.
But it does kinda make you wonder if the person who came up with this thing has ever had to use it during some response to a chaotic sudden emergency. I cannot imagine it performing as well as a standard second stage when it's suddenly critical that you do 8 things at once...
That said, I admit I haven't tried it. Perhaps I need to keep an open mind
:doctor: