I have a question- Will a V/V/T/3-way switch work? Think of it this way- switch in middle position is both pickups on, with a volume for each, thus like a standard V/V/T. Switch either left or right bypasses the other pickup completely, thus the P sound would not be affected by the bridge PU.
Currently dreaming of a Precision with NP4/Big Split in P/J location, passive, with the above electronics layout.
That's how I currently have my PJ Jazz wired.