Would be cool to be able to manage Extra dim directly from the main brightness slider, without it being separate. For example, when you move the slider towards very low brightness values, extra dim is automatically activated and gradually increased based on the brightness slider. From a UI/UX point of view, you could make the slider go "below 0", in which case Extra dim kicks in and adjusts gradually based on the slider. From 255 to 0 "normal" brightness is adjusted, under 0 the brightness stays to 0 and Extra dim gets enabled and the Extra dim intensity is adjusted instead.
