Just read the "T foil rudders - a complete guide" and am definitely sold on the idea of a T-foil now!
One thing that immediately struck me is why just a single T? Would it make any sense to have an additional smaller (less prone to breakage during heeling) T closer to the surface to increase energy recovery but which should not interfere with the laminar flow deeper down for the displacement reduction.
Or is that me missing something crucial?