I’ve been in contact with Gary Schoener. He’s appeared on a panel on Oprah talking about the subject, as well. Not sure if he’s retired or not but he founded or co-founded the “Walk-In Counseling Center” in Minneapolis, Minnesota.
Home - Walk-In

My experience with Dr. Schoener: he accepted a ‘cold call’ from me all those years ago and was the person to refer me to a great therapist knowledgeable about therapist exploitation, PrevT.
I feel they likely saved my life, at the time.

He’s not only an expert on therapist exploitation, he’s a great guy.