Black Lab,
You have shown something in that video I have asked several dealers about. That is, a front wheel generator ... similar to what we powered our pedal bicycle lights with years ago.
I have often thought that some type of generator that only operated when the front wheel is moving would be ideal for attaching heated gloves or additional lights to etc. That way the stock stator isn't stressed by having too many items attached to it.
After-all auxiliary lighting is really only necessary while moving. When stopped at a traffic light it is not nearly so important. Heated grips and/or vests etc. are the same. When I am not moving neither my hands or torso get real cold.
I could see it as an ideal solution for when you are riding 2-up. The pilot is already blocking all the wind from the pillion. If their heated vest turned off accordingly for the 60 - 180 seconds you are waiting at a stop-light, it wouldn't have time to cool off and the pillion should remain comfortable.
Nobody I know however has any idea who or where to get one. I don't believe that the additional "rolling resistance" to the front tire developed by some type of generator would significantly (negatively) impact power or gas mileage.
Just a thought.