Yup, I think you came to the wrong conclusion on the tape vs naked spine effects on sharpness. All using tape does is make a very minute difference to the bevel angle. It has no influence on whether the bevel is truly set or not. Bevel set meaning the two bevels actually meet all along the edge.

As Utopian said above, stopping adds a further refinement to the edge if done properly. I strop the night before which seems to work for me.

Bob