[Lombra]

I understand. While not an answer to your question, in cases like these I'd say you shouldn't be bothering. If a user goes in and deliberately sabotages stuff, that's really a futile thing to try and prevent. Nothing prevents someone from disassembling their computer and putting a screwdriver through their CPU, but why would they do that?

Don't bother protecting the user from themself unless it's something that's easily accessible or may accidentally happen.

Edit: As long as the library is accessible via LibStub and the callback object via the library object I don't believe there's a way to deny anyone access to it, no.