The configuration files labeled 8E, 16E, 32E and 64E are different on the Microstepping resolution side: higher the resolution, higher the accuracy, lower the slew speed.
In each file the "E" indicates that is the "Encoder" version, while the number indicates the Microstepping resolution.
Follow this path: StarGo2 Pro WebApp -> CONFIGURATION -> EXPORT CONFIG.
The Password is: AVgotosys
Inside N.I.N.A. is not possible to launch the ASCOM chooser from the Telescope section menù and, as long as this operation will be ot accomplished, the Avalon UD Telescope driver will be not available in the Telescope drop down menù, preventing the connection with the mount.
Read the procedure to make appear the Avalon UD Telescope driver on this article. First connection with the StarGo Plus/StarGo2 Pro driver with N.I.N.A.