I'm 100% certain you have thought of this, but have you considered something a little more "outboard" like? i.e. shave that wart off the bottom of the hull and smooth patch it, and come up with a small electric drive that you can tilt or lift up and out of the water when under sail? Could be bow mount or stern or whatever. Oversized trolling motor basically.
maybe a rack of trolling motors, linked together?
