No hpop stays full .Does the hpop reservior stay full, or drain off?
I do not believe it has a pressure accumulator, so pressure will naturally bleed off.
Did he try with the stock tune?
I have an old superchips tuner, when turned up to performance modes, takes longer to start. Haven't had my analog gauge on it yet to see where the pressures are. Engine oil pressure is read directly from reservior. Not sure if ecm must see pressure before it allows start.