For a vast over simplification of pressure vs volume.........lets relate it to electricity. A 20 gauge speaker wire will carry 12 volts(pressure) and so will a 00 welding cable, but only one of those will crank your car, because only one carries enough volume(amps) of electricity to operate the starter motor. I can crank the pressure(voltage) up on the small wire to 16 volts and it still won't crank the car.

So your motor requires a volume of fuel to run properly. If the pump and line can't supply that volume, no realistic amount of pressure increase is going to overcome the lack of volume.

As for the lower pressure, decreasing aeration of the fuel and the car running better...........that has been proven time and time again on the RACETRACK........NOT on a piece of paper