yes, I've used a unidirectional ESC, but this should be the same thing. It simply works on a servo signal and translates it into an output. The said "pushbutton" seems like that's what centers it so if you have a 128 (from your 0-255 range) (aka, ~1.5ms pulse width) output and you push the button that'll designate that the center, or if you have 6 it'll do the same, though leaving very little room for one direction. I would assume it saturates at the other end as well. the one I have is already pre-configured to have stop at one end and ramps up from there. Well, hope this helps.
-J