Good point Stringy,
I think ideally you'd want to have an extended aluminum mount as the only thing anchored to the hull, via the front and back hdpe pads and a pin sitting in the mirage drive supports, rather than mounting the pins on the centrboard itself. Then you could attach the centreboard to the aluminium mount (below the pin) with a metal (pivot) bolt at the rear and one or two plastic shear bolts at the front, so that when you hit something the centre board would pivot back about the rear bolt. I'd be worried about the leverage such a big board would have laterally over the metal mount and the hull though with such a shallow structure.
I think I prefer your daggerboard in a mirage drive plug idea as a less risky (but very elegant) solution
I notice that when I'm sailing quickly in a good breeze with my big sail in adventure mode, the standard daggerboard gives more than enough lift to stop leecocking, but in very light winds I could do with a board mounted further forward, for those times when I'm enjoying the sailing experience too much to want to put the. Mirage drive back in
. Just like a sailing dinghy, however, sitting as far forward as possible pretty much eliminates the leecocking