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 prefer LazyLibrarian over Readarr but it still leaves a lot to be desired for end-user usability. One of the big issues with ebooks is that data is a mess, with each book having a billion different editions with spotty metadata support that makes it hard to tell what is what.
Goodreads seems like it was a decent source of data for these types of projects but they shut off new API access a couple years ago and legacy access can go away at any moment. Hardcover seems like a promising API alternative but not sure if anyone has started integrating with them yet. Manga and comics seem to be in a better state, with a more rabid fanbase maintaining data but still nowhere near what’s available for movies and tv.
They use air pockets but they are of the stiffer variety that are fitted around each drive, not the super cheap and thin air pockets that just get jammed in to fill the box.