One of the things I found helpful about getting out of the specific / formulaic feedback was asking the LLM to ask me questions. At one point I asked a fresh LLM to read the book and then ask me questions. It showed me where there were narrative gaps / confusing elements that a reader would run into, but didn't realy on the specific "answer" from the LLM itself.

I also had a bunch of personal stories interwoven in and it told me I was being "indulgent" which was harsh but ultimately accurate.

That's a great approach. I find LLMs work really well as Socratic sounding boards and can lead you as the writer to explore avenues you might have otherwise not even noticed.

Given that humans are 'wired for story', perhaps you should consider indulging. These could be what makes the books stand out after all.