If you want simplicity I recommend skipping all self hosted solutions. You can set mihon to download X chapters ahead for offline reading and delete chapters as you read. On a kindle I’d recommend save as archive and/or cut tall images (webtoons).

Ebooks take no space.
Stick to calibre on your computer and transfer via netshare using a file browser (android: solid explorer) to copy stuff over. That’s what I do.

Mihon is the successor to takiyomi. It’s a manga website scrapper. But it also supports some self hosted solutions for reading across devices.

Make sure to add this special repo: https://raw.githubusercontent.com/keiyoushi/extensions/repo/index.min.json

Mihon guide here: https://everythingmoe.com/post/mihonguide.html

It really sounds like you’re trying to setup a centralized solution for media consumption and I might be confusing you with my recommendations.

I read on only one device so this works for me. Mihon supports self hosted solutions. ReadEra is just a nice reading client. I manage it with a file explorer and netshare (Solid explorer)

Android tablet phone here.

Manga - Mihon

Ebooks - ReadEra premium

I use calibre on my PC to manage ebooks, but I often download directly on my phone.

I use TTS (Text to speech, paid feature) to listen to my ebooks. Sometimes I use @Voice (free with ADs) to listen to books. It’s better for that.

I second this setup.

I have 3 ONN sticks and they do the job. Great for the price. Just sideload Kodi, new launcher, remap buttons.

I even paid for button mapper. Totally worth it.