Syil SX3 Spindle Control

Hey All,
Last night I finally used M3 and M5 to turn my spindle on and off. You have no idea how excited I am! I have a few questions though....

It seems the spindle turns full on and full off, is there any way to set the speed?

I am using the larger pulleys so I entered 200 and 3500 in the pulleys screen, per the manual. Seems nothing changed, what does this setting do?

The manual mentions the rotational speed jumper. I was unable to find it, are there various versions of the spindle control board?

Thanks,
Joe