TG, do you have a DVM? If so, remove your control plate and hook it up to the outside(coming from the vol pot) and middle lug where the cap is. Set it for continuity, and set your tone control full CCW. You should hear the continuity "beep" and it should be steady. Now rotate the tone knob CW until the beep stops. Note where you are on the rotation. This is where the cap is out of the picture. There is no "as far as we can tell". On every guitar I've done this test to, continuity is disrupted long before the pot is full CW. The cap cannot physically affect the taper. This is solely the function of the pot.