To get that little inductance on a coil that size that can take a serious amount of power with that much travel and keep a BL good all while being underhung requires a really crazy motor, basically this is just as "crazy" as the Uber 24" just scaled down, and the price would be similarly proportional. 10 of these with the same power and same enclosure volume would outperform the Uber 24" for a sealed system. They would work great ported too, and should run up clean really high. This is all still theoretical though remember.
So are we still talking about a 24" driver or multiple smaller drivers at this point?