I manage my ebooks using a self-hosted instance of calibre-web.
This allows me to sync my library to my Kobo e-reader using KOreader.
Also, turning pages is faster than with the stock reader of the device.
Also, turning pages is faster than with the stock reader of the device.
Protocol is atom based, chatgpt was able to make a custom OPDS server for my needs within minutes, it took another hour or two to fix and customize generated code.
I think it works using the file name of the epub. Not sure.