Extract ZIP, open about:debugging#/runtime/this-firefox, choose Load Temporary Add-on and select manifest.json. This temporary install is removed on restart. Permanent distribution requires Mozilla signing.
Disable older WideView builds before testing. Allow access to the video website and embedded video domains. Refresh the page, start playback, open WideView, and choose one video or all detected videos. Use the website fullscreen control.
No native apps, protected browser pages, closed shadow roots or non-video canvas players. This build has not been accepted in every browser/OS.
