I am getting a focus motor for my 8” edge HD telescope and noticed that it is built around a servo motor not a stripper motor. It can be controlled by software that use ASCOM, so I am assuming it will work with SGP. I am not sure if a stepper motor is better than a set I motor.
There are two ASCOM drivers for the Celestron focus motor, one for running it stand alone and one built into the Celestron mount controller for if you have it connected and controlled through the mount.
It doesn’t matter to the user what type of motor it is, from Celestron’s point of view it is practically the same as the servo motors used to driver the mount.