As i was lying in bed last night, I was giving this interesting thread some thought. It occurred to me that although Cricket Bats must be made of willow, baseball bats are often made of aluminium.
With an aluminium bat, you get a different noise, but the bat still has a weight, mass, MMi and CoR, and of course a MoE, and the shapes are similar whether would or Aluminium. In addition, the way it is used is different.
The question is really, aside from the pressing on a cricket bat blade, does it really matter whether it is a low density cleft, an overdried cleft, or a completely normal cleft? If a bat performs well enough according to any tests that you undertake, e.g. dropping a known mass on it from a known height and measuring rebound, and picks up in a way that you like, surely the skill and timing of the batsman is far more important in firing the ball to the boundary at a high speed than the size of the spine on the bat?
I'll give you the hypothetical situation of Marcus Tescothick's Mongoose challenge. You and he are both at Lord's with a bowling machine pinging down ball after ball consistently, and you take 12 balls each, sharing the same bat. Who is most likely to hit the ball over the Lord's pavilion?