While that may be a possible reading of the regulations, a project I was involved with got nailed for not having J-valves on manifolded twin 120's (and that was with divers with 2 slung deco bottles).
There was redundancy on the back gas, and two deco bottles, and they got cited for not having J-valves on the manifolded 120s.
(Very, very ***)
Just because OSHA cited you doesn't mean you were in violation of OSHA rules. Last year when we had an OSHA audit, 3 inspecters gave 3 different figures for clearance from a circuit breaker panel and it turns out all three were wrong.:shocked2:
Showing them their own regulation saved us over 100 citations and fines.