The top also defines the ANGLE of the edge when it contacts skin. A cap with a higher peak will shave different than one with a lower peak. If you have a thin , flat cap, or secure the blade without a cap, you can get the blade almost parallel to the surface of the skin and still have contact. Not so with a peaked cap. You make a great point about where skin contacts the cap. If the cap is curved enough and the blade extends beyond the edge of the cap far enough, the point of contact may not be at the edge. I'm going to have to check this out on some my razors. In that case, I agree: between the point of contact and the edge doesn't matter. The more I think about it, the more I think you are exactly right.
I was going to say that the difference in between the peaks and troughs in the scalloping may not be enough to effectively change the exposure. I think changes in the guard position have a much bigger impact on the shave than changes in the cap edge position. But I think Erik nailed it: The point of contact between the doors and the skin is behind narrowest part of the scallops, so they have no effect. Can you feel the scallops when using a normal angle?
No they're not in any way recognizable by feel - the Ming Shi just feels like an ordinary mild DE. best Regards goshawk
