I enjoyed your comments about orthotics not highly affecting the kinematics, yet providing invaluable aid of symptoms.
Just a few comments to back you up in your observations, yet I'm sure you've discussed these possibilities with your students many times.
1) Interestingly, Root maintained that you only have to control the last 1 degree of pronation (or maybe less) to have complete resolution of symptoms. He maintained that pronated feet are not usually symptomatic, only subluxed feet. So you need very little change in kinematics to feel marked relief of symptoms
2) I think Irene McClay did a nice job with the Blake orthotic study to show that it was the kinetics, not the kinematics that was so drastically changed.
3) I believe that many of the changes are not in the rearfoot to ground, but in the forefoot to ground and the forefoot to rearfoot kinematics, especially in the intercuneiform relationships. Haven't figured out the best way to measure these.
4) Most of the studies do not utilize each subject as their own control, but instead give averages for a large variety of foot types. For example, it would be interesting to see what happens only in those type of feet that are judged to have 5-10 degrees of forefoot varus with all other parameters nearly normal. Good luck trying to find such a population that is large enough to study.
So with those small observations, it would be interesting to try to understand the real reasons for so many of treatment modalities working, but the problem is that no one wants to develop their education background necessary to understand the real reasons.
With a politically correct happy holidays to everyone. best wishes for the new year, :)