Couple of things I disagree with your viewpoint.
#1 You mentioned that the assignment may take months or several months. I disagree. It should not take more than one or two weeks if you are prepared and experienced. Understanding the problem is the key, solving it the right way should not take long.
#2
You should be prepared well before taking the essay exam. You should not be writing till the end. Short and crisp but effective writing should get you there.