Selfhosted

It was a cool idea, but I could never get it to sync everyone's playback properly without constant buffering for all involved. We just sync manually by counting down from 3.

Good thing I chose jellyfin over plex. This is the main reason I got jellyfin.

My friends and I use syncplay + mpv for this. It works well, and even though it's designed around local file playback, you can add https URLs to the playlist. So this with nginx serving the files has been a great solution.

You can even play YouTube videos by adding yt-dlp to mpv, but that doesn't reliably work right now as far as I can tell.

LoL. That feature is literally the only reason I also have a Plex docker pointing to my library. But they’ve definitely not been supporting it for a while, because I don’t think it’s worked well in forever. Last few times I tried it with friends, we ended up having to just try to hit play at the same time.

Oh well. One less container now.

Dang that's sucks, I never used it but it's neat in concept

For anyone in that spot of being savvy-ish but having fellow users that finally got used to plex:

A work around is Xteve and owncast. I was successfully able to make an owncast broadcast into a "DVR channel".

Its cluegy but it does work. My tech level in this stuff is spotty. I'm used to stacks of tech but more for physical control systems (NOT consumer facing). But I was able to get that to work.

Edit: little bit of clarification: Xteve will let you add DVR to your plex server. It's possible to tie owncast into Xteve. That allows users to cue into a "DVR" channel which is kind of "simulcasting" whatever you're pointing owncast to. In my case it was a screen share of sportsball, but it could be whatever.