Lux is one case where a material can be a full-fledged light, with all attributes a light can have, so the strict separation of mesh vs. light which exists in Poser doesn't apply here.

Lux's area lights are real lights, for you don't just control luminance and color, but the full slew of parameters any other light has (you can even add IES files to them!...).

So yes, we need a way to easily transform any type of material, not just to a light-emitting cheat like Poser's "Ambient", but to a real light.

Really guys, check the Lux forum thread I linked to above.