there is a very easy to set up alternative using nordvpn (not free) + meshnet.

default apps download original files, no transcode options.

Streamyfin claims download any file transcoded as long as your server can transcode it. Haven’t tested it myself.

Audiobookshelf is absolutely awesome for audiobooks. Tho it’s possible, Jellyfin isn’t really very audiobook friendly imo. Just run both.