I did a google search and I think I answered my own question.
I found this thread that had some links to other threads. On one of them I found the HF couple that I was speaking to at MAHHA, TZ Brown - he is mentioned in the video on that thread. The video unfortunately does not show the spreader bar well enough to understand how it works. I think I will PM him and see if he might contribute to this thread and offer his ideas.