I guess it comes down to latency requirements? I would expect where latency isn’t a huge concern, the best user experience would be to start the new receiver b

I guess it comes down to latency requirements? I would expect where latency isn’t a huge concern, the best user experience would be to start the new receiver back at the last keyframe and fill the buffer up to “present” so they can start watching instantly, and keep a few seconds in the buffer for stability. In more latency critical streams where you still want the perception of instant video startup I suppose you would have to start at the last keyframe and then as soon as the next key frame came through you could just jump ahead.