Will there be a book of secret knowledge that only the initiated will be allowed to see? And they will all swear an oath to never input it into an AI system?

And then we'd also do that for all kinds of potential terrorism, sex-crimes, political subversion, and evil advocacy?

It would be the "restricted section" like in the Hogwarts library?

Post-training is not about "secret knowledge": it's literally about training the model in a RL environment on very specific tasks (including, potentially, cyber exploitation). It's just as compute-intensive as pre-training these days, if not more (given that several checkpoints of the same pre-trained model are being released, showing sizeable gains in real-world capabilities for non-trivial productivity tasks).