Somebody please guide me into how I can maintain a reliable multi-device ebook library that works offline and actually syncs books' progress.
I read on my Kindle, phone and computer. I've managed to put together something that syncs the books themselves across devices using Syncthing, Calibre and EPUB reading programs for the respective devices, but I can't get book progress to actually sync across devices and it's annoying.
I know Calibre lets you host a web server, but it still doesn't sync progress to Kindle (afaik) and it still doesn't count as an offline solution.
I have looked up but I haven't found much. This can't be that niche of a problem. Anyone autistic enough to have figured this out?