I found a video on youtube of a single wing spinner series of footwork for the spinner back. The footwork in the video is very similar to what we use for our QBs in the Spin. We take a shorter first step toward the line.
We rep the plays on air at least 30 minutes each practice, more time earlier in the season. The timing is critical to the success of the exchanges from QB to running backs.
Play for Fun and Winning is Funner!