Ok, the Jog Incr++ and Jog Incr-- sets the actual step size of the cycle jog step on the MPG (TAB on the keyboard).
Upon thinking about it, I do not think there is a step jog choice for buttons as that is what the center jog wheel is for. Set your step increment in the flyout (TAB), and then the center wheel will jog to whatevcer you set that to. I have mine set to .001", and if I need to ove it faster/further, I just use the outer ring to do that function.
Hope that helps?
Dave