For the NMs that drop singles, I suggest it drop at least up to three plates, with one being being a guaranteed drop, second being a possible up to 30% and the third up to 15% per kill. As for NMs that drop bags, riftcinders, and riftdross, those should drop in their own slot that is not shared with weapons and armor, and the drop rate increase to at least 45% chance.

Even if the drop rate is tied into using Phase Displacer, that fine. Use none, get a better drop rate.