Oops, I read too fast; you're using the rising rate fuel pressure (from a stage 1 DA SC kit?) That will increase pressure under boost and get more out of your 20lb injectors. The stage 3 kit if I remember correctly, gets rid of the RRFP gizmo entirely and instead just uses 28 lb injectors. The advantage of using bigger injectors is that when you go open loop (boosted hard acceleration), then the open loop "maps" already in the computer will now be "magnified" by the ratio of your new injector poundage relative to the stock (18 lb) injectors. The stock fuel pump works fine at 28 lbs. but if you push the envelope of the M62, eventually you'll want more flow rate than the stock fuel pump can deliver
If I remember correctly, Metric mechanic put in a Ford Mustang fuel pump in my car (drop in fit apparently) to increase flow rate, but you probably won't need that until you get well over 200hp. (a Wide band O2 sensor can help keep an eye on how lean or rich you're going under boost)