maybe it's a prank easter-egg put there by his Majesty Geoff Crammond to annoy the living daylights out of us the users in trying to decipher the way it works.
I guess he must have assumed that one day, in the very distant future, the users will discover how to modify the tracks, so placed the Advanced Lighting mystery to give them enough time to make up their minds about doing a 5th title and completing it in time, while the users are busy thinking about the mystifying Advanced Lighting?
Probably not, but it could be.