I haven't changed the surface on my NRP, but I have changed it on the Daredevil. Same cover. I took the shine off on the Daredevil. Definitely smoothed it out a bit. I've been considering doing it with the NRP, but that ball has worked very well for me with the shine on. One of the few balls that has. Actually, Code Black is also good shiny. Maybe the asymmetric cores match up with shine better than symmetrics for me.
I wouldn't be afraid to try it, anyway.