stealth type rudders are great sailed with them for 2 yrs now and work a treat , I sailed out and in through breaking waves dumping on a steep shingle beach at loch ness , was far easier than last time i sailed a boat with rear pivotting blades that nearly got snapped off when launching on a H5.9SX , as for controllability with blades raised , it works no trouble at low speeds as John Pierce always has said .
Developement as suggested would be to be able to rock the cassette back and forth , think I read in latest Yachts and Yachting that this is what the latest Int 14s are doing , that would be interesting and relatively simple I pressume .

However unless you can adjust the wings whilst sailing I cant see much point in adjusting attack , conditions throughout a whole race raely stay the same to get a benefit from any other sort of adjustment . Stealth rudders are nuetral untill bows try to go down , then they maintain the constant waterline plane