Simply put that’s really difficult to do and against the guidelines.
Your OBS would have to be broadcasting one stream per scene (so 2 scenes = 2x bandwidth, 3 scenes = 3x bandwidth and so on)
Then you need to have something to handle video transcoding (aka either multiple twitch stream channels (so just use squad mode instead) or your own video transcoding stack)
Then the extension needs to be able to play video, and video is not allowed under the guidelines last I checked.