something else to think about...and you'll noticed bareshafting/papertuning and group testing..is by changing your bh, you start effecting spine on arrows. Its part of the tuning process, getting the bh right will get rid of (if close enough in spine to start), the lefts and rights.
I prefer to get really close to a target and as long as I'm not grossly over/under spined, get my np on. Than start tweaking shafts and bh to bring them in. Basically play with spine and or length to get the bulk of the left/right out, than start fine tuning with my bh. Knowing that if the bh is overly high/low you need to make an spine or arrow length adjustment.
I prefer bareshafting and as I get closer to final tiller I back up. shooting a bareshaft 30yards is not overly difficult with proper form and a tuned bow. You'll know immediatly if somethings not right as you increase distance. Normally I will stop at 10/15 yards and shoot for awhile but do enjoy testing arrows out to 30 and see just how close I am. Gotta be the long dark cold winters effect
Note...do NOT start out at 30 yards LOL start a few feet away and work your way back as you bring things into final tuning.