I actually emailed them about this. Unfortunately, I was still slightly confused. but here is what they said:
Basically, If you were to have your front binding mounted all the way toward the tip of the board, the back binding would need to be moved up one hole set from the bottom of the board to have a twin set-up. If you had your bindings set down 1 hole set on the tip, then you would have to move the back binding up two hole patterns in the back, etc. I hope this helps!
I used the second and fourth holes from the head of the board on the front foot, and the 3rd and 5th holes counting from the head on the back foot. Hopefully that all makes sense.