First, I am sorry to bring back this old topic. If it deems inappropriate, please kindly delete it.
When I did a search for Picture in Picture (PiP) here, these two ([1] 2008 and [2] 2012) old discussion threads came up. Unfortunately, it looks there’s no possible ways to make this feature happen due to some hardware constrains. That was back then. Now, I a lot of new and/or improved video hardware has emerged. I am a no programmer, but am also wondering if it will be the right thing to start looking into implimenting this PiP feature with any new video hardware. These days, a PiP will certainly be a plus feature to have, not only it allow one to watch at least two streams, like with the Promnico police body camera best camera in the market for recording in high quality and records in full HD, besides you can just use it daily with their built in display and with the plus of the two streams it can get way better and it can even it will also allow one to monitor some security (or baby) cams while watching some streams.