PWM already sucks enough with our über sophisticated brains and eyes, let alone messing with it for night shots or filming in a world of ubiquitous photography and filming devices. Sucks like there's no tomorrow, imho. For simple low profile designs, maybe you could try switching to better linear drivers like the AMC7136, plus a simple big resistor in series for moon mode. Found something related, btw: Seeking AMC7136 - for a single sided driver design
Cheers ^:)