I heard similar things separately so do find those details believable

I agree that stuff is rife in the underground

I understand Grof believes these things. That's quite a far cry though from paranormal beliefs being central to much of psychedelic therapy.

Yes, I've read Grof. I still wouldn't agree with the characterization that much of psychedelic therapy relies on paranormal beliefs

Ok I've listened to Doblin's words you've cited. Here's what he says right after. This is not really consistent with paranormal beliefs being central to psychedelic therapy, which is an extraordinary claim

What does "much of" mean here?