[elhigh]

Any improvement is an improvement. Freebeard is right, a curved profile that more closely resembles the template would be best, but I think a straight wedge that dips below, then back above the template's profile would give the airflow a chance to reattach. I'm guessing here, Aerohead would be a much better reference than I.

I think any reduction you can make to your wake is a good thing, and if you leave a few percentage points on the table by being conservative, well, that's still better than not caring.