So, I'm reading your posts on this thread and can't help but wonder what all the talk about long hoses and deployment are about.
The long hose was utilized to solve the specific issue of traveling through areas too small for buddies to share gas from a single source.
For BM this was the perfect cure for this situation. SM has the advantage of being able to pass the whole thing off to your buddy.
So your buddy is OOA, you allow him/her either reg for the oh sheet moment. Once that is over with, unclip a bottle and pass it to them.
If they are SM you just need to swap bottles. There is no dire need what so ever for a long hose while diving SM.
This is one of the great advantages if diving SM independent doubles. So, if someone chooses to dive 2 short or long hoses, as long as everyone on thier team is aware of it, there should not be a safety issue. If anything, passing the bottle off is likely to be safer that being tethered by a single gas source.