I just released a new version of the livechat plugin (v7.0.0).
It comes with a full federation support: you can now chat on a remote Peertube instance using your local account! (nickname and avatar included)
This is a feature I had in mind since the beginning of the development. It is now a reality!
This version provides also arm64 CPU compatibility. If someone can confirm it is working, it would be nice (this requires to update the plugin, then uncheck the settings «use system prosody»).