Well, I tried a little bit of every thing. I built up the shelf with some thick leather and skived the ends to give it more radius. I then got some dental floss and built up the serving under the nock to get a little better nock fit. While I was at it I wound more floss under the area below my arrow nock to creat sort of a lower nock point. Still not quite where I want to be but I'm much closer with my bareshafting and the bow seems to shoot a little better as well.
As I experiment I might try raising the shelf even more, or try an elevated rest to see what effect that has.
My wife likes to use Glide dental floss which is super slick, so I highjacked some of that. It holds the arrow secure and seems to release it cleanly as well. And, as a bonus, when I come to full draw, I get a hint of minty freshness lol.
Thanks for all of the tips!