Maybe I am missing something? Whats the purpose of a 7' hose in the first place? The value escapes me if Im not exiting a confined space with another diver.
I sure dont want somebody more than arms-length with my second stage unless we cant get through the same hole. I absolutely want eyeball-to-eyeball contact, visibility allowing, when the situation has deteriorated to the point of sucking off the others bottles.
The purpose for a 7' hose was to allow single file exit from a restricted environment.
Many of us see value for it in OW as well. If I need to have someone closer to me during an air sharing ascent, I don't have to undo the full length of hose, but I always have the option to. If I need to control them I can still grab their harness strap.
Air sharing is not always a result of an OOG situation. I had a friend who got bad air recently. When they got to depth they started feeling badly and noticed a bad taste. They made a calm ascent on their own, but they could have shared air with someone on a long hose with good air while making the ascent if needed.
If I'm doing a submarine dive with someone, I expect those people to have solid skills. If they bumped into something and accidentally sheared off a hose causing a sudden gas loss and a subsequent gas sharing experience, I don't need to be eyeball to eyeball with them on ascent. Having the freedom to move away from each other a bit and put a bit of distance, especially if we're having to hang on a line is beneficial. I don't want to hang on in stiff current with my buddy right on top of me. I'd rather them be able to be a bit above or below me while we're playing flagpole.
Diving with a long hose in OW isn't a necessity, it's convenience. But doing so keeps my gear the same, my configuration the same and my responses the same no matter what type of diving I'm doing. It doesnt add any extra complexity or problems to have it and it brings the benefits already mentioned. To me, its one of those "I'd rather have it and never need it, than need it and not have it" things.