Long hose is for cave/wreck diving. It does have some benefits in other diving, but it would stik to octo setup for rec diving. Why complicate things, octo works well for rec diving.
It's true an octo works well enough for OW recreational diving, but it's the same as saying a Model T works well getting you to work. It's true, but that does not change the fact that there are far better tools for the job.
The long hose works far better, even in recreational diving.
Here's another way to look at it. I've donated gas three times in real world OOA scenarios and in all three cases it was on along hose. The ability for an OOA diver to have enough hose to not have to hold the reg in his/her mouth and to be able swim normally along side you during the ascent is priceless.
I've also offerred a reg proactively to low on gas divers to complete a swim to the planned exit/ascent point to a) ensure they'd have enough gas and b) ensure they would be able to to have ample gas to conduct an ascent, safety stop and BC inflation using their own gas.
In all of the above cases, the receiving diver was an instant convert to the long hose.
IMHO it in no way complicates anything. A long hose primary and bungeed secondary cleans up the hose routing on most divers, eliminating a hose looping out over the shoulder and greatly simplifying gas shares while accommodating the reality that a real world out of air diver is more than likely going to take your primary, so developing the concept of primary donation both provides a known to be working regulator to the OOA diver and acclimates you to the idea of going to your readily available and easy to find primary.
The only real change that needs to be considered is perhaps keeping your snorkel in a pocket rather than on the mask itself.
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I was certified to dive in 1985, and even then at that comparatively late date I still encountered divers who felt an octo was unnecessary and that buddy breathing worked just fine, and in fact buddy breathing was a required skill in my cert class in 1985. It's amazing in retrospect to realize that older/more experienced divers and instructors were willing to stay with an inferior configuration and practice just because it was familiar and that change, even good change, was by definition bad because it was
change.
I fully expect that 20 years from now, some OW diver being trained today to use a short hose octo, will remark after 20 years of diving experience in a similar retrospective look at changes in training and practices how primitive the short hose octo was and express amazement that experienced divers and instructors could be so stuck in dogma and routine and be so resistant to change as to not accept the long hose primary and bungee back up as a vastly superior system. He'll also wonder and comment on why it took so long for it to be come the recreational OW standard. And of course 20 years from now, they'll be speaking about the short hose octo the way we all speak now about buddy breathing - an antiquated and difficult to perform practice that has long since been replaced.
