It was yet very difficult. As author you would like to make it fun, and repeat next year. When he decided to confuse, add lines (and main clues, images) for the last keys in loosefull concepts, within all writings and images, it was when the solution líne got lost.
At the same time a supersolution sense. Closing all features. Mind the extreme south, North, East points (added) difficult but easy, again showing up, suggesting the true difficult 1,000,000 Michelin clue.
The cities importance is discarded by previous contests, and the spiral form. I believe, to find Chartres as easy it may sound, without internet. A know France, play askings around, plus intrigant maze in a little town. Could have even started there, all its creation.
The main clue is Dabo, talefull, intrigant. Then he continued probably too much phocused in map riddles. Just his call. A little short probably. From Chartres, Bourges, something different (no map riddle) shall have been great. Maybe two or three more steps.
Sounds easy, but it was difficult enough.