This is by no means a medically informed opinion, but I am of the impression that fasciotomy is to release the fascia. It seems to be risky, according to many postings on the site. If 'thermal surgery' shrinks the plantar fascia it seems to me that would make it worse, since tighteness would case more trouble, while stretching is the prescribed thing for it.
Maybe I am missing something but shrinking the fascia seems like it would make PF worse. I don't know much, though.
happy hunting, alan k