I wouldn’t say excessive STJ pronation has a direct cause/effect to Plantar Fasciatis. If that was the case then why when many people who report PF say they feel better barefoot when barefoot would tend to allow way more STJ Pronation and MTJ Supination (which is foot pronation)? I blame crapy shoes, excessive sitting, and poor mind body awareness more than anything (don’t blame the barefoot of most folks).
I think improving this condition starts with a full body approach, improving sensory and motor awareness to the foot(walking and feeling different surfaces), enhancing breath, working sub threshold of pain, and then enhancing their sphere of function over time. Throw out the orthotics(not for all, but many) and work slow.
Remember, everyone is different and pain doesn’t come from tissue it’s an opinion and output from the brain.