At this level, not at all. 3 stars means that every single serving is perfect by itself, the quality of the ingredients, the texture, the taste. Everything.
You cannot allow yourself to not be perfect. For example, you cannot serve something new where you know it is really good but fails a bit on the texture side or it is hard to produce so the quality varies a bit, not a lot, but a bit.
If he goes out of the system, he can reintroduce this little bit of freedom.
As a programming analogy, 3 stars is like every single piece of code you produce is perfectly structured, integrates nicely in the software, respects the conventions and idioms, has no code debt. You cannot just patch a bit and see how the users react and refactor later. It must be perfect for the user from low level code to the interaction as soon as you put it in the hands of real users.
I am full of respect for such decision.