Hello! Really great mod with flexible option, it adds a lot of needed depth to light system.
Just wanted to make a [SUGGESTION/BUG REPORT].
I have noticed my diggers working in total darkness. Turns out, if you have big connected space (game considers it as a room >3500 tike size), some narcoleptic dupe, sleeping somewhere causes all hat lights to be turned off. My suggestion is:
Before turning hat light OFF, check if room have size =<120 tiles.