I actually have that keyboard, but haven't yet tried arranging it vertically. Can you use wrist rests when you use it that way?

Not sure how you could use wrist rests, or why you'd want to. For a horizontal keyboard, wrist rests prevent you from bending your wrist harmfully. Of course, they also let you get lazy.

For the vertical layout, the spacing of the keyboard prevents wrist bending: the two sides of the keyboard are roughly shoulder width apart. When you aren't typing, the natural thing to do is put your hands in your lap.