Here's the fairing after shaping with the sanding batten. All the sharp corners have been rounded over.
Care is needed when sanding foam.
You can easily remove too much material and wind up with a coke bottle shape in the middle of your airfoil. Next, the voids under the mounting plates will be filled and any tears or gouges that happened during shaping will be repaired. But you just saw off the excess and sand again. This foam cures with a smooth skin, but its interior often has larger bubbles and voids. Trowel it on and sand it off.