Interesting, I agree mostly, but disagree with a point. I feel that the middle position does matter, in that the absolute bulk of the wood should be where you hit the ball the most for your most productive shots. However, if you made your Velocity profile for someone who likes higher middles, to their ideal pick up, balance and weight, I think you are right in saying that they will be able to score runs with it almost as well, as I agree with your statement about the playing area. I have a Bulldog shaped to a lowered Amplus profile, which has the main bulk of the wood around 10 inches from the toe, but just immediately above that, the bat feels dead, but it feels pretty responsive around 2 inches from the toe.
I have a feeling it has to do with the handle of the bat, as it is where you hold the bat, (pivotal point?) so as you swing it, there will be an area which will be the ideal contact area, ie. the playing area, which is pretty consistent with bats the same length, assuming they are handled and pressed well. I wonder if this affects the playing area of a LH or a LB bat though... Have you had a chance to do an experiment on the playing area of different sized bats with different handle sizes? Maybe there's some sort of link… Or maybe I'm just talking BS.