Proper Accumulator Tank Pressure

I was taught to run the bladder pressure at two psi below the pump cut in pressure and that always worked great for me. The reason is, so there will be a little bit of leeway so the bladder will still have some cushion affect just before the pump comes on. I always use the same gauge to check the pump cut in pressure and to pressurize the bladder.
Running the bladder pressure exactly the same as the pump cut in pressure would give the max drawdown but I never tried to get that precise … flip a coin. Craig