I bare shaft tuned my arrows with out the rope installed. I havn't noticed a difference in arrow flight after adding the rope.
FWIW.One mistake I did make was burning the ends. When I did this it shortend the rope a little and with the slick ends you could here the rope "rattle" in the arrow. Now I'm inserting the rope all the way till it hits the insert and cutting it flush with the shaft end. I don't burn the ends but use a very sharp knife. I then insert that end into the nock. Totally silent and about 75 extra grains.