Is there a streaming-native way of encoding multiple camera angles simultaneously in a video? The ability to toggle between different angles is a feature on DVDs and Blu-rays that IMO is underused but awesome for educational videos where different aspects or angles of a demonstration might be useful.
Youtube has multi-stream capability and I've seen one streamer use it years ago to let you pick which multiplayer user to spectate. I assume they used separate streams inside in the .m3u8 file used for HLS, much like how you'd do different resolutions. Haven't seen it done in years.
.mkv files natively support adding an arbitrary number of video tracks, though player support is kind of rare. (it's _ by default to cycle video tracks in mpv)
On Mac, I'm using Continuity Camera with an older extra iPhone I have + Elgato Cam Link to hook in a DSLR.
Then I use OBS Studio to mash them all together, you can then use some plugins to switch between cameras live while streaming (or recording).
