I understand your point. But there's one way where this thing might work (if it wasn't so hard to install..ie... making it a return system).

You are right, maxing out the fuel system via something like turbo/sc would warrant a fuel pressure upgrade as one way for providing more fuel.

But in NA applications, the FPR might help in one select situation. WOT. WOT fuel maps are set. So if you upgrade enough na mods, one might run into a lean WOT condition (aka open loop operation). At anything less than WOT (aka closed loop), the o2 sensors should be able to handle any na breather mods. So if one could up the fuel pressure up a tad to compensate for a possible lean WOT condition (due to na breather mods), it would represent a cheaper (abeit less precise) way of getting the a/f back in line.