With College Football and NFL seasons starting up in the States, a multi-screen option for Live TV would be a nice addition to the Emby feature set.
I am thinking of what the WatchESPN app offers thru their Web Browser access. The ability to open a multi-screen window that breaks into four (4) screens that allows you to select streams (Live or Replay) for each and then go full screen. Audio is from whichever of the four screens you have as active.
I can accomplish the same right now with the HDHomeRun Quick View TV app. I open multiple instances of the Windows app and then snap them to each corner on my 110" projector screen. Equivalent of four (4) 55" screens. Would be nice if this were a remote friendly option from within Emby Theater and the WebUI clients.
I have only seen it in Web Browsers at the moment and not any of the Win10 UWP apps (FS GO, NBCSn, WatchESPN). But, Fox Sports Go just released a multi-screen solution for their Apple TV app.