Cannon.................as far as changing the dimensions on the inside of your pots, it really wouldn't be necessary if you are using the same thicknesses in your striking materials and your soundboards. This is if you are trying to distinguish between plain, blasted or anodized aluminum, and this is the reasoning behind this statement. If you are using aluminum that is 62 thousandths thick, (same as slate) then what would be the difference in the distance between the bottom and the top? None....blasted is the same because any difference in the overall thickness would be on the top of the aluminum, none on the bottom, anodized aluminum would only gain an overall thickness of less the .002" or .004" at the most considering the amount of anodizing you do on it. So, again there would not be any major reasoning behind moving your internals.
Now as far as sound coming from your pot, this may be effected somewhat because of the type of materials used, with aluminum I leave .1260" between the bottom of the aluminum and the top of the soundboard, this gives me just enough echo and ring not effecting the kind of sound I am looking for in a pot, with aluminum I want loudness and high pitch with a fast break that would end up with enough rasp to be able to hear it as my striker stops. I hope this helps you my friend, ever hear the old saying, if it ain't broke don't fix it? pappy