There's no "under the body crossing" going on. If you were in true single file it crosses over the tops of the recipient's legs not really any different than coming off the right post in doubles. The donating diver holds it in position on the back of the recipient's thigh just like any other single file long hose touch contact donation. It makes not a whit of difference which side of the body it originates on.asinine for air sharing yes. You give someone a stage bottle if they need it, you don't try to exit single file while air sharing. 7ft hoses crossed underneath a diver is very dangerous and quite uncomfortable for the guy receiving the gas since it is being torqued out of his mouth and uncomfortable for the guy in back because the effective length of the hose is MUCH shorter.
I don't disagree about when you're not sharing gas in terms of comfort though it does make the short hose on the right weird since it can't go behind your neck, but this is part of planning for the worst and hoping for the best. If I have to share gas with someone, under no circumstances do I deem it acceptable to have a long hose crossed under their body and making a ~135* bend to get into their mouth at a tight radius, that's asking for trouble. It is almost as idiotic as 5ft hoses or the concept of passing primary bottles off. If we were talking true exploration dives only where the only chance of encountering another diver was someone from your team of support divers that had similar configurations then we can have a different discussion, but unfortunately it does center around yahoo's diving in Ginnie, Peacock, and the rest of the tourist caves.
When you dive the SK with doubles where are your stages then? All left with the SK left too?