[jee7s]

Absolutely legal. R83 allows for "storage tanks" (yes, it's plural in the manual) upstream from the regulator. Additionally, the tanks need to be compliant with R75, R76, and R77-K.

Tanks on the "high side" before the regulator store more energy per tank than those after the regulator. This reduces compressor short cycling. In a 2 minute match, that means the compressor may not have to run at all. The "low side" tanks allow for faster actuation. The regulator is most definitely restrictive.

Rules of thumb? Depends on the setup. If the compressor is constantly running, then more tanks before the regulator. If the actuation is sluggish and the regulated pressure takes a long time (more than a few seconds) to recover, then more tanks after the regulator. Side effect is that more tanks means more time to charge which means a longer initial compressor run time. But, since you can charge the system before a match, a well sealed system shouldn't encounter a problem if you allow for enough initial charge time.