They do this in both the NABPLEX and the MPJE.
With the MPJE, since that is the exam I am most familiar with, you get 90 questions, but only 60 are the real exam. The remaining are being tested for use in future exams. NABPLEX/MPJE are both a computerized format so you cannot tell which is experimental and which is a real test question.
As far as slacking on the experimental section. How do you know that the headings actually mean anything and they aren't all jumbled together as stated above? From a strategy viewpoint if you are pressed for time and won't finish, obviously you leave experimental till last. But why take the chance of shooting yourself in the foot by leaving the section blank or coloring the dots if they are playing games with you?
This is only your future we are talking about. Be the best you can be.
