I have mounted an old William Optics Crayford microfocuser on my C8 Edge HD, and attached a pagasus stepper motor, driven by a Pegasus UPB.
I spent significant time finding the proper settings that would allow autofocus regardless of the filter used, and with a nice V shaped curve.
I found backlash set IN at 100 steps, and 150 steps for focusing are working fine. The default 30 or 50 steps do not work.
Other settings left at their default values (8s pose, binning x2, 9 iterations).
One caveat, though : to start autofocusing, you must be already very close to focus, otherwise the routine chases the focus point forever.
Hence once found, lock the mirror down, and forget about using the scope focus button.