This sounds like something I'd be very interested in since I've gone whole trips without hardly touching my brakes using throttle to slow so I hit lights, etc. We know how much attention folks pay to the speed of scoots in front of them so this seems investigating. You probably know I dislike modulators intensely but having lights appear when you decelerate without using the brake seems like a way to provide better visibility without annoying flashing.
Was kickstart project and now in production. http://vololights.com/