reverse in the revo tranny is pretty simple. There a gear on a slider shaft which moves forward to engage the forward gears, and to the rear to engage a small, cheap looking plastic gear that controls reverse. You don't need to Y to a controller or anything. After you shift it to reverse, forward on the throttle will be reverse. Then you will need to shift it back. My concern with a brushless motor is that the torque will be much too intense for the cheap little reverse gear. You would not be able to limit the EPA on reverse without affecting forward throttle.

I this is where the teckno kit benefits, because of the clutch setup. It should be a bit more gentle. You'd just need to watch your finger while reverse is engaged.

J.