Basically, if you want to use Video Feeds, you need to stack the windows.
Because the Feed is going to show the window at whatever size it it.

I personally don't use feeds, but many do.
Game Source (for XSplit streaming) will disable Aero, which is needed for Video Feeds.
I could stream with screen regions, Aero enabled and use Video Feeds.

The combination of instant swap, to whatever window needs my attention...
And Jamba forwarding whispers...
I haven't really felt a need for video feeds.
But with a bit of playing around, feeds could display exactly whatever info is wanted... such as combo points or whatever; it definitely could have its uses.