A t-foil was tried on a twelve about a decade ago... and lasted about a week... The problem that they found was that as the bow was lifted up by the kite, the t-foil turned into a lifting foil, making the boat jump into the air and crash epically.
I know that we're taking up a few high definition head cams up to Brisbane. I was thinking of maybe sharing them around the crews as much as possible to get a really good first person view of what its like to steer (and maybe mine) a 12 downwind... also thinking of a few cool camera angles on...