At the larger sizes like this model I can't imagine that you'd get anything but pluses. And you've got the right idea for the cuts. Although you may find that it's easier to skin the rear of the slat with glass cloth and epoxy instead of veneer. And if you can rig up a way to slit the skin and then templates to hotwire the front off then you could use mylar and foam to push it back against the wing and keep it lined up while the back skin cures.