An idea might be for now to use a Polisport Lookos EVO. It uses a solar panel to keep battery charged which if you didn't use light during day seems like a good option. It also seems like it would not be using as much power as a bolted on KTM light once someone does figure out how to get into the bike power. Done right (note I am not an electrician), how far off is the idea that it remains powered by the solar with a bypass feed when the light's battery gets too low? It uses two 5 watt 12V lights.
Polisport Lookos Evo Solar Headlight System | 39% ($106.66) Off! - RevZilla
Polisport Lookos Evo Solar Headlight System | 39% ($106.66) Off! - RevZilla