Supination Resistance is another one of those topics that I find myself writing about a lot (eg here and here)and something I have been banging on about in my Clinical Biomechanics Boot Camps for years.That is how important I think that the concept is.
The concept has its origins in the concept of overpronation probably not be all that it is cranked up to be, so rather than focus on “overpronation” perhaps he focus should be on the forces that are associated with the function of the foot and pronation. It just makes a lot more intuitive sense o be focusing on the forces rather than the motions. It is the forces that actually do the damage to the tissues rather than motion. Motion is not painful.
I have certainly done a lot of research on it and unfortunately never quite got to publishing it. I did summarize most of the research done in this post.