I've been eyeing my A-1 back for a couple nights now thinking along the same lines. I'd love to have $1 Billion to blow and just have a panel of experts sit at a table around me to problem solve the solution.
Main thing I can think of is the battery space. Depends on power consumption requirements.
Wouldn't even need many extra wires. Just some external switches. On/Off and when on the sensor is dormant waiting for light. When it sees light it saves the image. If you need more power, make a screw-on mount like the power winder A (only it can be half an inch thick), and a single lead to the back to connect the juice.
Oh, how I've been designing it in my head. I just don't have the means or expertise to do it.