I call BS on the general idea that there is utility in being able to reach one's valve diving a single tank.
I would bet that most/the average open and advanced open dive classes do not discuss the diver manipulating their valve while underwater. And for those who believe that it is a life saving technique when splashes and find that their valve is closed, perhaps those who have died did so because they were trying to figure out their valve, this scenario does not happen at 30 meters it happens close to the surface, perhaps they would have been better served by dropping their weights and swimming up? If they have no compressed air in their lungs their is no danger of DCS/embolism.
I can see this as a necessary skill for a solo diver, but solo divers are not the majority. The industry still preaches safety in buddy teams. I think it would be more prudent in an out of air situation to take/receive the octo of one's dive buddy, get the breathing under control, and then have them check to see if their partner's valve is open.
Perhaps the problem that people find with dive masters f*%&ing with peoples valves before they splash is because there are lots of divers that fail to do a good buddy check before a dive and the DMs find that people are often forgetting to open their valves? I have seen lots of divers not do buddy checks or relatively inadequate ones....and it gets worse with experienced divers due to things like ego, normalization of deviance, and confirmation bias...the tendency is to not remark about crappy buddy checks when its not ones own buddy team. I watched a very experience diver come close to losing their tank last weekend because they didn't get the tank strap tight and their buddy team did not do a proper buddy check....they tried brushing it off after the dive blaming the netting on the tank as being old and loose....the reality is the strap was loose and not straight....but the tank strap is something that should be checked during the buddy check just as one should be checking that all straps are routed correctly and not twisted.
How many of us have seen folks skip the buddy check on the second or subsequent dive of the day with the same partner? I see this all the time...this is just poor discipline and eventually leads to problems.
Advocating that being able to reach and manipulate one's valve as a single tank recreational diver, diving in buddy teams, just seems like a fix for a problem that does not exist and already has a solution for it. There just does not seem to be a good reason for a diver to be holding their breath while sinking further away from the surface while trying to figure out IF it is their valve that is the problem....go up or go to your buddy and use their alternate air source.....anything else just smacks of a bit of a rediculous notion.
All that being said, there is nothing wrong with developing the skill and having the ability to do it, but lets not fool ourselves into thinking this is such an important life saving skill for the recreational diver when it is not and their are better options to exercise.
-Z