Keep in mind that the return line from the fuel rail is also feeding the surge tank. Also remember that a fuel injected engine uses no more fuel than a carby engine, just needs more pressure, not more volume.
So, the extra fuel that bypasses the injectors is going back to the surge tank, plus the fuel from the low pressure pump.....there is wayyyy more fuel being supplied to the surge tank that the engine could ever use. And, I would imagine that the surge tank is actually seeing about 2-3psi of pressure because of all the excess fuel being supplied to it......besides all that...it works......I used it.....