Please add Collaboration Stream Feature Like Pixiv Sketch.
I have an Idea that can possibly beat Twitch, but to me mostly a boost help for artists. It's add multi-stream setup and options for streamers like Pixiv Sketch. Pixiv Sketch has an options where you choose to allow anyone to drop in stream and draw with you. And also video between two or more can fully adjust the video size.
Please take a look at Pixiv Sketch. And please wait until streamer that's collaborating and click on it. You know there's stream collaborating when a circle of another user is on the lower right corner of the stream preview.
Oh! And take look at the mid slider bar and move it when you looking in a collaborating stream to see how they adjust the video size size for streams. That what mixer needs.