When I was there, I could tell the therapists watched the clock as they'd say, "We're out of time today", regardless of what we were in the middle of.
IF a therapist talked for any additional minutes, it was to threaten kids into behaving. They'd go into the isolation units and say things like, "Your parents know you're in here, they want us to keep you in here until you start behaving, and I'm not letting you come out until you........(insert request to submit will to WWASP here)". As people in the treatment industry, they are unethical sellouts.
I have heard that parents might be able to purchase additional therapy at some programs, but everything is viewed as a billable expense in WWASP programs. Their markup on basic toiletries turns airport gift shop owners red with envy.