I have, and use Calibre with LL instead and it still requires a lot of hand holding and manual grooming to get a clean library.
My big issue with Readarr is that it had a hard time fetching data for various popular and/or prolific authors. So if I wanted to fetch all the books for a particular author, there was a high likelihood it wouldn’t actually fetch the necessary book data to do so.
I’ve been using Hardcover. Still very much a WIP and community is still pretty small but it seems very promising with a public api and ambitions to open source.