Agree with all, and with the clearances you have, you should have good oil pressure, assuming cam bearing clearance is good. That front plug can be done in the car, although you may swear about it and will need to be careful not to drop it inside.
However, that M57B won't help idle oil pressure either, as I understand, it's basically a standard pump with a HV spring (or close to it). The bigger gears of the HV pump typically give better idle oil pressure and the spring determines the peak, so it did exactly what is expected.
Last thing I would bring up is the oil mods, in some cases, you can break through if you open up the primary galley out of the pump into the block, it'd likely be worse that you are seeing, but I have stopped doing it. I'd start with that dribble valve and then see where you are