I don’t think it’ll work because Plex gates everything with a sign in to their online accounts, so auth would have to go through them and there might be server-to-Plex verification going on too.

That said, I’m very interested in this space - I’ve been building a music server that provides compatible APIs for Synology and QNAP mobile apps, with a few more on my todo list. I’d love to include Plexamp so if it is possible please let me know!