I am puzzled by this also. You say that the rifle is punishing with full house 130gr loads, but you enjoy the lesser recoil with the PP boolits? maybe I missed something but you need to be pushing these boolits as fast as copper jacketed boolits, thats the whole idea of PP rolling. Now if you are already at max pressure, dont worry with going any further and being unsafe.
Large patch fragments are not good. That little bit of hold that the patch has as it unwraps, can throw your boolits in a spiral like 303guy says.
If you are still using the 100% cotton velum, lose it. Try green bar printer paper. I'm pretty sure that the boolit fairy sprinkles magic dust on the factory where this stuff is made, because it seems like every body ends up with a winning combination with this stuff. If you dont have access to any, shoot me a PM with your address and I will mail you some (I have a lifetime supply). I started out with velum but my opinion is that it is too strong for use with boolits and I had better luck with almost any other paper, except walmart receipt paper.
I am very impressed with your powder selection! I wish I had that many options! It seems like that IMR4350 would be a good one to try IMHO.