Discussion: something I learned from PT: ...

something I learned from PT: massage arch of foot culminating in ball of foot, while at the same time flexing your foot upwards toward your shin. Then maybe destress toes, jiggle them a bit. Repeat motion for a couple of minutes, maybe twice a day.
You never know, right? At least it might give you a better sense of what wrong...

Whatever this is, it is NOT soft tissue.

Well, I didnt say anything about soft tissue. I had something like this and I learned that the adjustments to my foot that the movement provided, and adjusting my form a bit, helped it considerably.

Sorry, thought you were advocating massage, which helps soft tissue but is generally a very bad way to treat connective injuries. At any rate, the pain is at the other end of the metetarsal, up in the actual arch. That, combined with the fact that I'm a supinator makes it very unlikely this is impact related. Still haven't ruled out a stress fracture, though that's seeming less likely as there is still no sensitivity to pressure from any other angle. Probably a mild sprain of some sort.