I was last Saturday on a Schweser Mock live exam, and must say time in the morning session is really essential.
I was always around half an hour earlier done in Level I and II, both morning and afternoon session.
But this morning session really took me until the last minute. You should really think what to write or not.
It takes incredible much time to write down the calculations. If you have to calculate the Covariance between two Markets and write down the complete formula and then your calulcations where you plug in the numbers, then you probably loose so much time that you might not finish.