Yes, multiple regulators are allowed, so long as they comply with the pneumatic standards. They can also be placed anywhere.
Although, you may not want to use a pressure regulator. If you’re worried about breaking your robot or the field in some fashion, there are alternatives. We’ve had great success with flow regulators, which limit the flow of air into a piston, slowing it down, but not limiting the overall force. This would slow down the entire movement of the piston, but would probably be similar to running the pistons at a lower pressure (speed wise).
You can also look into using adjustable cushion pistons. I know that most Bimba pistons have no dampening or partial plastic dampeners at the end of each stroke. Festo pistons have many options for cushioning, ranging from automatically adjusting air cushions, soft plastic internal cushions, or even manually adjustable air cushions.
This year, we opted to get the manually adjustable air cushions. I believe that they use an internal check valve that cushions the piston in one direction at each end. basically, when going from in to out, the speed is not slowed down at the beginning and the middle of the stroke, and is slowed as it reaches the end. But at the same time, it does not dampen the movement as it moves inward from the extended position, and only cushions as it approaches the fully inward position.
The manually adjustable cushions are controlled by a set screw, recessed in the piston housing. Turning this will change the overall strength of the cushion and its effective dampening distance within the internal stroke.
From my understanding, Festo pistons are one of the only such customizable pistons readily available to FRC teams. Standard configurations include many strokes and bores and include all dampening options except no dampener. Pistons also have an optional internal position sensor (effectively a linear potentiometer), but I can divulge further at a different time.
Standard configs usually ship in 1-2 days, custom one’s ship at a similar schedule from Germany.
Sorry if it’s coming off like I’m one of their reps or something, I’m just a senior who loves their quality products