I mean: If there was something you could add to the prompt to consistently increase performance why isn't it in the system prompt already?
If it's all about clarifying a couple of local idiosyncrasies, shouldn't it be able to quickly get them by looking through the repo?
Does anyone have an example of a CLAUDE.md that really makes a difference for them?
In general, this article would really have profited massively from examples of good applications of those patterns.