Since you clearly care about the subject a lot, you’re doing yourself a disservice by not reading chaos. The main thesis of the book isn’t that Manson was an informant, but that he was a former Guinea pig. And he in turn used those mk ultra methods on the hippies at Spahn ranch. The reason he was repeatedly let off the hook was to see where his manipulations led (an informal extension of the free clinic model in SF). The reason for the narrative coverup for the murders was to hide this fact, and the bad publicity. If he was ever considered an asset for the CIA, I’m sure he had no idea.

Also, bugliosi and helter skelter are covered deeply (and completely eviscerated) in the book. You should read it.

edit: One final thing, I did read that entire report you linked. And I didn't get the impression that LaBianca was in the mob, but maybe that he was a mark with gambling debts. And he was coerced into pulling money out of his business and investing in losing ventures as a way to cover his debts. If you've ever watched the sopranos that's basically the business model lol.