Autofocus with feedback (like centering)

Sure...

When user starts the evening, they input (perfect focus) and (fine step) to "SuperFocus".

(perfect focus) is the current focuser position for perfect focus with the Bahtinov mask.
(fine step) is the step size the user likes to use to achieve (perfect focus).

Now, when SuperFocus is called upon, the algorithm...

1. Calculates HFR like is does now at (perfect focus).
2. Increments by (fine step). Is HFR lower? If so, increment again. Is HFR higher? Backup and done.
3. If HFR higher, go the opposite direction and repeat.

The key is small focus steps. Not the big steps the current algorithm uses. Big steps introduce non-linearities in SCTs and other scopes.

So not too much unlike the closed-loop Centering. (perfect focus) is the reference frame and (fine steps) is the differential.

"SuperFocus" can be enhanced in the future to increase or decrease (fine step) for faster and more precise convergence. But this may not be a great benefit (TBD).