heres a bad photo of dale with great technique
he has the front foot over on the outside rail and the back foot inside.
surf coaches talk about working the diagonals- say a natural footer doing a forehand turn will have pressure on the toes on the back foot and pressure on the heel on the front foot. that gives him the guide control.
on a sup because it so wide you have to shift the feet across the diagonals.
having two feet pressuring on the inside rail gives way less control and you lean off the board. the photo of that girl dj posted is a perfect example of it going wrong.
thats another reason why so many people fall off doing cutbacks- they are off the centre of the board and then drop their inside shoulder and they fall off.
this was explained to me awhile ago by a australian team coach.
try it when you surf- i think you will be surprised how good it is
cheers