Something that I have started doing is to tell it to spawn a reviewer agent after every code change, and in the Claude/rules folder I specify exactly how I want stuff done.

Mostly I use it to write unit tests (just dislike production code that is not exactly as I want). So there is a testing rule for all files in the test folder that lays out how they should be done. The agent writing the tests may miss some due to context bloat but the reviewer has a fresh context window and only looks at those rules. So it does result in some simpler code.

You dont need to measure the code complexity, you can completely hallucinate those numbers if you feel that code is too complex and then watch how LLM will respond.

Thats how you end up goodhearts lawing your way into simplicity eg duplicate code. Thats like the whole takeaway of the article at least for me.