Could be interesting. I coated the parts on my 930 JM Pro in Nickel Boron. Did the bolt and carrier, bolt handle, carrier latch, recoil spring plunger, piston, magazine tube, and spacer tube. My gun runs like a dream.
Tuflehundon
Did you also do the barrel and receiver? I wasn't going to focus on the internals but might based on your experience. Do you have any pictures you can share?
NP3 is very slick and will make everything slide smoother & easier, while also being very easy to wipe down after shooting. I've handled a bunch of AR-15's with and without the bolt carrier group plated with NP3, you can actually feel the difference running the charging handle, it just feels smoother with the NP3. So I would recommend doing the internals if you are having the rest of the gun refinished, for the few extra bucks it's well worth it IMHO.