Mel did a test of fuel PSI vs injection timing and higher then stock i think once it was at like 6psi it was advancing the timing. there is a thread here somewhere on it.
Maybe on a speed shop pump with a much higher gallon per hour flow rate, but on these things, , as I said, ZERO DIFFERENCE. I tested teh things, and found none. I have a pressure regulator sitting under my hood right now disconnected as there is simply no reason to use the thing.