Deebster

Ebooks: I use Calibre locally and Calibre-web on the server (read-only metadata db, I overwrite with the Calibre version as tagging, etc is far easier on desktop).

You can connect Koreader to Calibre-web and until maybe a fortnight ago you could jailbreak a Kindle and use Koreader instead of the default software. Now you’ll need to manually move files over, or use the email-to-Kindle option (probably a bad idea, but I expect Amazon can tell if you’ve side loaded pirated content anyway). Nowadays I buy from not-Amazon sources, strip any DRM and send it over.

Manga/comics/graphic novels: I use Kavita on the server and I use comictagger on desktop to fix the metadata.

I’m happy to use different set ups for the different types as they’re quite different experiences and specialist tools work better.

That reminds me of Netflix’s Chaos Monkey (basically in office hours this tool will randomly kill stuff).