I’ve not seen this question asked, maybe I missed: do you believe the itching/aching is coming from the TA or the smooth muscle? Or both?
“I think the soreness/aching is a sign of the tissues being successfully stressed and the itchiness (which comes a day or two after the initial soreness/aching) is a sign of a reparation/healing process. For instance when I stretch the skin on my penis I will get very itchy there after a day or two, but it’s a shallow itch since it’s the skin. I’ve also gotten deep itches at the base when I have worked the ligs good.”
So if that is so, where it comes from would depend on what was being stressed.