as far as i know , peltiers conduct heat in a liniar way.. so that in the areas where the heat source is on the low the block will only have to cool the heat from the tec itself still not perfect but thats all we got :P
as far as the holes , ill pressure test them for about 20-25PSI for a cupple of hours , if ill see a leak or its bowing a lil , ill add anther set of holes
btw , i've just finished the machining programing , i might do it today if we'll have the a blco in stock