This test should be used by everyone. Generally the bareshaft will act backwards for fingers and release shooters. This is generally, sometimes they act backwards of what they should.
Somepeople add weight to the back of the shaft, some don't really just a personell thing. I fletch all of my arrows up, and just rip the feathers off and leave the bases.
As for the left bareshafts, if you are a right handed release shooter, generally this means weak arrows. To fix weak arrows you can do many things. 1. Shorten your arrows 2. decrease draw weight 3. decrease point weight. Any/All of these should move your bareshaft to the right. Now, if you make these changes and it is not helping 2 things could be happening. 1. Your arrows are simply way underspined and you need to buy stiffer ones 2. Your bareshaft is acting backwards and you need to reverse these steps to make the arrows weaker. This is how I would fix the bareshafts (Make sure you use more than 1 bareshaft)
Sorry Bow but looking back through your post I never saw you mention the step back method. I only saw you talking about bareshafting, and I saw alot mention about moving arrow rest.
For the end process (if neccesary) then I'll move the rest to get exact impact (I'm talking micro adjustments here) between fletched and unfletched
Doesn't that mean that it tells you the perfect centershot?