I tried the readarr and other options. They work sometimes but not enough to rely on it. As others mention, there's no standard naming and also, lots of people use their library card for Libby access. I also think there's a bit more of a direct link to authors so I'd prefer to buy the book unless theyre super well off anyway. To be honest, I can't see the arr's working with LibGen having looked at the open issues on integrating it, it just doesn't allow for scraping in the same way.

For me, I self host openbooks (uses IRC) and select a download straight away, which to be fair, is about the same time as searching / finding a TV show if you are after one book. I have exposed it behind an SSO so can access it on my phone and download the book straight away when someone gives me a recommendation. Most of the time I just add to a running note on phone and go through it every few months when I need more books.

It's fairly quick for multiple books but not sonarr levels of ease. The downloads go into a calibre monitored folder which then does the automation (naming, conversion if needed etc). I bulk email the new books to my kindle with one click. Calibre-web is on read only for a nice browsing experience and to read on other devices if I need to (althogh no page sync). It's a bit of manual work but I find it is not too bad and in 10 minutes I can load up enough books for months.

Occasionally IRC does not have the book so try manually searching on prowlarr, and download on sab or transmission. The downloads are almost instant so I then just wait and copy them to my downloads folder (I could probably automate this step too with tags but it's so infrequent).