Last I checked, if you wanted to download media to a mobile device to watch later, you could only do that at full quality. Has that changed?

It’s really easy to set up if you use Docker.

I want to use Jellyfin, but the clients just aren’t up to par with Plex and last I checked Jellyfin won’t transcode downloaded media.

No. What you’re describing is completely normal when using something like pihole.

For most things I’d recommend Usenet as well, but that might not always be the case for niche content.

For example, I think MaM is better than Usenet for audiobooks.

Yes. It’s fantastic.