Duncan't Do It With 13 Bits (not as described anyway)
But you are cheating :)
This is not a legal competition maze. Do you have a legal maze that
Duncan cannot solve?
Still, point taken.
While I must confess not to have studied Duncan's method too closely, It
seems that this maze does not break the concept, only the
implementation. Since a wall-follower can solve it, perhaps the first
job of the minimalist solver might be to see if wall following brings
itself back to the start without visiting the middle. In that case, it
would then have to start adding walls.
It is too late for serious thought. Perhaps I will have another look