Re the full-aileron cross-control suggestion a few posts up:

As I understood it, you were giving full rudder also?

Wow, I've never heard anything like that suggested before.

One thing I'd urge you to further explo how much variation in airspeed can be tolerated before the glider is no longer in a stable spiral? E.g. if the airspeed accidentally increases by X mph, do you the dynamics change enough that you go out of control? The dynamics that keep the various turning forces approximately balanced, and the various roll torques exactly balanced, may be extremely airspeed-sensitive.

I'm not guessing one way or the other, just curious.

S