I stopped using Calibre because it turned out to be more annoying than simply emailing an epub to my designated kindle address. I've never had anything removed. Most of the content comes from libgen.
Easiest is with KOReader. You start a server in Calibre then connect to Calibre in KOReader (not via the web browser). At that point it's like you plugged it in via USB, you can add/remove from the device from your library.
I have my Calibre install setup with the content server feature which makes your Calibre library accessible to any device on the local network. I can then transfer the books to my Kobo by using the browser and hitting the content server's IP address.
I can't remember all the specifics of how I set it up and honestly i've not used it in a while because I used it to get all my old Kindle purchased books on (which was a lot) and i've not booted the docker container since.
Is this a reasonable work around/alternative or have I misunderstood? If so, I apologise. Oh also, I think I had to do some custom stuff with my Kobo as well to support this functionality, but I don't remember it being difficult. Got it all wrapped in an evening of tinkering.
Yeah, I personally don't see any need to maintain a digital book library (like with calibre) when libgen is so accessible. Email to Kindle is a great feature; I've also never had anything unexpectedly deleted.
