I read most of that (think I missed the last few chapters, but he was out of Elan and had done some traveling)--it was horrifying. There's also a 3 episode documentary on Netflix called "The Program" where the documentary maker revisits the now closed school where she went (The Academy at Ivy Ridge) and by episode 3, she's followed the money to one family behind a lot of these institutions. But as she and former AaIR students actually see other facilities far from where they were locked up, they're all carbon copies of each other, they're all just the same punish-for-everything camps with no escape. Fucked up that there's like a formal recipe for how to do this to families and not get caught. And that there are so few legal protections for children.
The podcaster host Brace Belden of TrueAnon was forced into The Monarch School as a teenager, which had a similar curriculum to Elan. His podcast takes some deep dives into the treatment of students as part of "The Game" miniseries. Episode 4, in particular, focuses on how the Synanon organization transforms itself from a cultish and violent drug rehab operation into an even more predatory troubled teen outreach organization.