I don’t think Plex Media Server uses a very externally-edit-friendly configuration system, and thus the Plex module just enables the server. Normally after enabling the service, I access the localhost:32400/web interface, link the server to my plex.tv account, and then manually teach it about each of my libraries. In theory, a one time operation (I tend to backup/restore
/var/lib/plex since it also contains metadata/art/watch data).
If you don’t care about freedom (in terms of source code license), want good mobile/web clients, chromecast support, things like “live watch parties”, etc, Plex is easy to recommend. It also remains the only media server that can do live-transcoded, adaptive-bitrate, seeking-enable streaming (due to a small
ffmpeg patch someone should liberate, combined with DASH/hls players).