Rick,
Scubapro did the same thing very briefly on some early S600's and G250HP's by incorporating a balance chamber that removed all pressure on the seat when the reg was not pressurized. They discontinued the practice after a very short period of time and reverted to the older regular balance chamber.
SP went that route to keep up with Atomic (Apparently viewed as important at the time given the defection of SP engineers to form Atomic) but Atomic has stayed with the practice despite the greater complication and many potential downsides of having the system open any time the reg is un pressurized.
If regulators were real life support then there would be a certification required to work on them?
I work on life support regularly, if an engine quits running or a wing falls off or a propeller goes away on it's own then pilots and passengers tend to get upset. When I complete a job I sign it off with the authority that goes with the A&P/IA. Who exactly guarantees with a legally required signature that the retail dive business clerk knows anything at all about regulators? Bicycle mechanics go to school or apprentice, who exactly trains dive equipment "mechanics" and I use that word dishonorably in that regard as they are unworthy of the title, mechanic.
I agree the average scuba tech may not even know how to properly use tools let alone understand how regulators operate. I have seen some techs in training classes that are just plain scary.
On the other hand, it is pretty hard to make a living soley as a reg tech so it is hard to require someone to spend a year or two in a training course - and reg repair is frankly no where near as complex as what is needed and required for an A&P rating.
On the other hand, some aircraft mechanics leave a lot to be desired as well.
I lost oil pressure in the right engine of a Seneca because a mechanic left a pocket knife on top of the oil cooler. Obviously it violated the "never leave a tool in the engine" rule - but I can see where it could be easily missed as there was no "spot" for it in the tool box. Still, we had words when I got back.
Another mechanic reversed the ailerons in a Bonanza (an admittedly hard plane to work on by GA/single engine standards.) I discovered that during a control check. More words were had back at the hangar.
I had a really badly rigged Citabria try to hop off the edge of the runway on takeoff. It had been re-engined with an 0-360 for banner towing and rather than change the incidence of the vertical fin (admittedly a major pain), they just increased the incidence on the left wing, which promptly stalled as soon as you added back pressure on a soft field/short field takeoff. Being young and stupid I did about three take offs playing test pilot with it to see how slow I could lift it off without without things getting interesting. It had a VMC well above the normal stall speed for months until they got around to fixing it. It was fun to watch other pilots fly it for the first time, as everyone wanted to see how much difference the extra 30 hp made on a short field take-off so everyone who flew it tried to lift it off at mnimum airspeed on their first take-off. We were a cruel bunch.
Finally, I had the stabilator trim stick in the full up position on a Warrior right after an annual inspection. That is a close as I ever came to dying in an aircraft and my arms hurt for a week. I never found out exactly what caused that.
In contrast, reg repair on the other hand seldom kills anyone even when done badly. Most often the problem is tuning it a bit light, with a mild freeflow resulting. Less common are leaks and problems with regs that are just worn out and or new parts that are not quite right (leaky poppet, etc) and again the problem is normally a less than catatrophic leak.
Rarely you will get a failure to deliver gas type of failure. I have only had one of those ever occur on a reg I worked on and it occurred with an older R109 where the lever slipped off the poppet during the first dive after the rebuild requiring a switch to an octo. It tested fine on the bench after service and after it failed once the poppet was reseated. The lever looked fine, but I replaced it anyway as I suspect it just had too much flex in the arms and or a lack of sufficient tension keeping the arms together.
In either case, a good aircraft mechanic or a good reg tech are worth knowing and holding on to.
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