Not enough distance difference as a result of the pivoting to pull the T-foil in tight.

The radius from the fullcrum to the point where the line enteres the rudder boards is too short.

Maybe have a pully on the stern and a clear on the rearbeam so the skipper can activate and deactivate the T-foil ? (an idea I had for the F12) But still have the problem of the line stretching resulting is a flapping T-foil possibly damaging the rudder board itself.

Wouter