I think it is easier to drive on forward and exit backwards.
On the resort beam figure looking to the front of the train.
At the Contemporary you board and exit on the left side.
At TTC you board on the left side and exit on the right side.
At both Poly and GF you board and exit on the right side.
At Magic Kingdom you board on the right side and exit on the left side.
On the express beam, looking to the front of the train:
At TTC you board on the left side and exit on the right side.
At MK you board on the right side and exit on the left side.
On the express you always must go on one way and off the other.