5.0 GXi-E LP fuel pump

My 2005 FW 210H recently became unable to reach full power under load. Now at FT it will only reach 2500 to maybe 3000 rpm. We found some particles on the fuel pressure regulator screen and cleaned it. Pressure in the rail was steady at ~50psi under all conditions. Motor starts right up and idles well. Checked and changed fuel filter, no paint or water found.
Found 0 psi at Low Pressure fuel pump port under all conditions so I believe this to be the cause of the loss of power. Checked for and found voltage to LP harness when key is turned to run position? Plan is to remove pump assy and replace LP pump and check for paint failing in the reservoir.

Assuming this is my issue, how does the failed low pressure pump prevent full power ?
Is there any other thing that I should check?

Low Pressure pump keeps the High pressure pump filled. High pressure pump does not have enough lift to pull fuel from the tank. You are simply running out of gas.

That makes sense in that the HP pump alone can only pull enough fuel from the tank to run at 2500 rpm steady state. Now it’s a matter of determining if I want to disassemble the fuel cell to replace the pump or swap out the entire cell with a reconditioned one from mancavemechanic.com. Appreciate the reply!