Options
In this page, I will go over good starting values for all the options.
I recommend using your own step size, but for the presets, I found step size 2 like the sweet spot, as it is very accurate in focus, but not too small, to don't detect hfr changes.
As you can read here, stepsize 2 equals 3 small steps. Here you can play around with the values until you find the best one for you. For me 0 + 2 always worked best (big steps: 0 + small steps: 1).
A further explanation to the step sizes can be found here
You can set the exposure time to any value, as long as NINA can detect stars. I found 5 seconds as the sweet spot, as autofocus doesn't take too long then, but NINA is able to detect plenty of stars. You may want to adjust your stretch factor then.
The Reset Auto focus is running button is useful, when the validation says "Autofocus already running", but there isn't any Autofocus running. When you click it, it will reset the Autofocus state and the validation error will be gone
