It's called PIP with televisions, multiple feeds in a single screen. I watch anime on HDMI1 while I watch a movie in the PIP screen from the TV feed.
It would be easier for the person patching this together, if Hitech did it based on a new view source menu function as a two window playback option. Same views menu as single screen. Looks like fixed external camera and internal in this film. Then the timing in the two windows would be the same. Manipulating two exported avi versions can get out of sync.
You would still have the loss of fidelity in the smaller window because you are shrinking your 32bit big screen into a key hole. Maybe even the ability to resize both screens. As a visual training aid that smaller screen takes too long for your brain to make sense out of it when you have to refocus your eyes and search for a common reference point. Equal sized screens will be the easiest for learning purposes.
My wife works extensively with training online and offline, so I get an earful about how people have been tested for optimal online learning and the results.