First, we teach Octo. breathing swimming side by side with the standard length octo hose and it isn't a a problem at all. Second, why would a pair of recreational divers who aren't in an overhead environment have to swim horizontally and not upwards towards when they are sharing air in an OOA situation? You say "Lots of situations," give me some examples please (it is very late here and I am too tired to think of these many situations
).
Not a problem,
Firstly, the standard hose length for an octo is far too short, especially when swimming side by side. I've seen this by showing examples to my students (hundreds of OW certs). at best, it places stress on the receivers jaw and at worse, completely pulled out of the receivers mouth. it can also interfere with inflator use and adversely affect buoyancy. Most agency standards do not sufficiently cover touch contact to navigate anything other than a straight ascent. The extra length of a 5' or 7' hose gives a lot more forgiveness in all of these situations.
Further, I don't consider an air share an "emergency", with proper planning (rock bottom etc) this is just a dive ender not a last ditch effort to stay alive.
Situations, other than cave/wreck that a team could not go directly to the surface....
1. heavy boat traffic (this being the most common)
2. local regulations require it (shore entry and exit)
3. must return to anchor line (diving on a wreck or reef)
4. water conditions directly above too rough, must navigate underwater to protected bay. This could include surface currents and/or waves.
As I recall, you are a supporter of the standard configuration, non technical and dive in pretty benign conditions....I could be wrong.