I was thinking about an encoder on the wing itself but the what if the actuator on the far side ran at a different rate? It would still twist the wing and you'd never know. With just one actuator it would be fine.

I wonder if an actuator will move fast enough to position the wing in race conditions? The heavy duty actuators I have seen are pretty slow and race conditions change very quickly. They would be the simplest off-the-shelf parts to use but if they don't deliver, they aren't worth anything.

Another place to look for parts might be in the CNC world. A servo motor and an ACME threaded rod or ball screw would move much faster and servo motors usually have an encoder built in. Looking back at Peter's original description, the system already uses pushrods up to the wing, so I would look at a nut up on the wing with a short length of screw and then a rotation shaft down the the trunk. More effort to make, but fewer moving parts, probably lighter and it could move the wing much faster.

Another limitation is the 12V supply; no over-volting anything to get more speed or torque.