I've never taken a class. If think that if I were in a team envionment that I'd get gas from a team mate, then turn off both tanks in the event of a o-ring failure in the manifold system. This would allow you to preserve as much gas as possible while you deal with the failure enough to start using the gas again. It could also just be easier to make an ascent on your team mates long hose. However, If your in some position where you're not able to easily able to get gas from a team mate, the it would be easier to disconnect one tank, attach the second stage or deploy a stage rigged second stage, then turn off or disconnect the second tank (depending on which tank was turned off). I'm just thinking through scenarios and solutions. Either way, you shouldnt be without any gas at any time, typical team based rock bottom planning would work,
and you don't have to dense to determine that their is a solution. I don't think that it's necessarily any more complicated than dealing with the 9 valve failures, but do require somewhat of a different process. Again, just thining it through shoulldn't be that difficult.
And again, I still think that a traditional sidemount set up is still the best current solution, particularly for true sidemount passages where you'd likely be scraping the manifold against the ceiling regularly. However, I wouldn't hesitate using a z system for some types of diving.
and you don't have to dense to determine that their is a solution. I don't think that it's necessarily any more complicated than dealing with the 9 valve failures, but do require somewhat of a different process. Again, just thining it through shoulldn't be that difficult.
And again, I still think that a traditional sidemount set up is still the best current solution, particularly for true sidemount passages where you'd likely be scraping the manifold against the ceiling regularly. However, I wouldn't hesitate using a z system for some types of diving.