Ampd VS UniversalMediaServer

Correct. I run mpd on my desktop machine, then connect to it from a client either running on my desktop (https://github.com/floren/Ampd) or on my phone or my laptop. However, regardless of where my client is executing, the music comes out of the speakers attached to my desktop. If there's a way to stream music from the server to the client, I am not aware of it.

DLNAmpvRenderer UMS

You can give a try to apps like Universal Media Server, they usually do the trick on Windows.

Download and Install Universal Media Server: Go to the official website (https://www.universalmediaserver.com/) and download the latest version of Universal Media Server (UMS) for Windows. Install the application by following the on-screen instructions.

I've never used a Jellyfin media server. I've usually just used Universal Media Server and it does read/stream/transcode iso files on the fly and stream them to any DLNA UPnP device on your network

You could try streaming to your PS3 via https://www.universalmediaserver.com/

After you have your SBS video, you then have a few different choices on how you want to play it on your Quest. You can play it on your computer with VLC and connect to your computer with BigScreen remote desktop in SBS mode (not the best because the controls for pause, rewind, ff, are difficult to hit this way), you can buy Skybox and play it off of an SMB share, you can buy Virtual Desktop and stream it from your PC, or you can setup a DLNA server such as Plex or Universal Media Server but not Window's builtin DLNA server nor Jellyfin and play it in BigScreen, Skybox, MoonVR, or any of the other video players that support SBS video played from a DLNA server.

Also, the newest version of Universal Media Server has a new feature that will do on-the-fly conversions of 2D content to 3D. I haven't tried it yet, but do have a guide on how to set it up for Quest 2 saved somewhere. Ah, found it. Not sure how that compares quality wise to a ripped 3D Blu-Ray.