I was looking around for some examples of code for this and found one with a variable for Break. This is not my expertise, but maybe it's an example for what you are looking for.
github.com/adafruit/Adafruit-Motor-HAT-P...t_MotorHAT_Motors.py

Good point!. In the python library BRAKE and RELEASE modes are explicitly defined and are available. I just noted they are also declared in C++ library . I will try using RELEASE in the driver's code and let you know when it's ready for tests (probably over weekend).

After closer look I found out that RELEASE function is not implemented in C++ library. Therefore release is achieved by resetting all PWMs after stepper motor finishes its travel to destination. You can checkout the latest code from github for testing.

Today I mounted everything together and took the motor for a proper spin. I can confirm 14,000 steps is all I need for full travel.
The process takes about 225 seconds. It's rather slow, but I can live with it as my prime focus is mostly in. But if it is safe to increase speed, that would be nice.
I also found more backlash in my complete drive train. 100 doesn't appear to be enough after all, 300 or 400 should do the trick.
Final thought, as a driver for DIY focusers, other users may desire the ability to select within options the drive mode (Single, Double, Interleave Microstep) that best suits their choice of hardware. For instance if somebody chooses a stepper with 5:1 or even no gear reduction; they would probably benefit from Microsteps.

Excellent. I'll have a look right away.

I'm glad everything works for you.
The speed value cannot be higher than 255 and now the driver lets you set maximum 250. So it's rather the problem of high gear reduction ratio for the motor than slow speed. I will increase maximum backlash right away. Checkout the sources in 5 minutes.
Let me add selection of various modes in a future release.

It looks like resetting the PWM did the trick. Nice work!

I had a chance to use it tonight. And hats off to you Kaczorek, the driver works beautifully.
All I have left to do is address a few mechanical details. Even so the autofocus routine did settle on a good focus after about 10 shots.
Thank you very much.

Have a good time while focusing

Joystick controls don't appear to be functional. Dialog will report Focuser aborted messages, but does not abort. Messages appear after reaching position. Focus In/Out reports nothing.

I will take a look at joystick controls. Abort focuser function is not implemented so it will not work.

Thanks Kaczorek. Take your time. This is just a report and I'm not even sure I will be using a joystick in this way.