I bare shaft/group tune, (2 bare and 4 fletched) starting at 10 and working back to 50....when they all have the same POI and the same tail angle in the target then I know my nock point and center shot are dialed in for the arrows.
If the nock end of the bare shaft is hitting tail high....move your nock point down, and vice versa......same thing with center shot.....tail left, move rest left, and vice versa.
Confused yet? I am.LOL
I have never tried it with really stiff arrows, but marginally stiff will work fine....marginally soft wont......especially shooting fingers.