I've been pondering over the same question, but also on an enterprise scale. For example, how could I scrub the customer data, like name, domain, etc., before sending it to LLM if my Claude code is using some MCP to fetch and debug an issue?
I mean, hooks are nice, but they are messy to manage/operate for many developers at a time.
https://github.com/softcane/cc-blackbox
I started investigating the proxy path, which I think would be useful for such scenarios.