Well tell him I did think about that - BUT the Steinberger is very expensive! AND it sticks back quite a long way, which would be great for balance but would negate much of the advantage of the headstock chop. I'd think going the 4+2 MM style headstock would save on some length, and the body can be cut away right up to the bridge. I'd guess this would only be a matter of a cm or two longer than the headless option. + headless is damn ugly...
Status LED's for charge would be no issue, actually that power bank has the input on the top with the power button and LED array, and the output on the side, so I might be able to slip it into a cavity and plug the power in, leaving the port and LEDs visible!