hmmmm... So you can now rule out the Hobbs switch for sure since the symptom did not go away but rather stayed the same. Simply increasing the pressure is only going to put a band-aid on the problem and cause you to lean out higher up in the RPM range at WOT in my opinion. If you had a megger you could test the integrity of the windings but i doubt they are breaking down or you would be likely experiencing fuses blowing. However brushes wearing down and dust buildup from that process could cause increased resistance which would cause the pump motor to run at reduced efficiency as someone else has mentioned. if you knew the static resistance of the armature of a new motor you could check yours to see if they have increased resistance which would then be reason to pull and have load tested. That's all I have for you on this. The Fore Innovation module could be limiting voltage to the pumps due to an issue within that module but you can verify that by measuring voltage feeding the pumps.I doubt that would be it however. Last you may wish to check to see if the pumps aren't clogged on the entrance side causing your restriction down in the pump. BTW running E-85? Are the pumps and lines rated for E-85 if so? Not for flow but for resistance to break down by the E-85. Someone I knew had an issue with that after goign to E-85 some years back when that trend first started catchign on.
Let us know what you find. I'll ask some guys at work and if I get anythign aside from failing pumps or clogs I'll post up.