There are API programs that let you stream your live simultaniously to multiple platforms at once. Right now Jitsi can only stream directly to Youtube but this API may help people stream to other channels like Twitch, Andrew Boon maybe we can add this service to ours?
Usually Restream rtmp key is added to your local streaming app, like OBS or Ecamm or Zoom and then you can also let it stream to a custom RTMP - like one on your UNA site. I suppose we can look into sending a stream from our server to Restream for further distribution, but then you add up latency. Will certainly investigate.