Bob issued a plans update for the Patrol which can be found here: http://bearhawksafety.com/Patrol/february2020.html
To elaborate more, Bob says while looking at a photo of a Patrol in flight, he noticed the oil canning in the three bays on each side of the wing strut attachment point. His desire to reduce this was not a matter of structure but rather to improve the effectiveness of the airfoil, by more consistently maintaining its shape. In other words, the airfoil will perform better without the deflection. This is why there is no need to make the change to airplanes that are already past this point of construction.
In the plans photo to the right, the leading edge is at the bottom. There are two arrows pointing to the location of the new stiffener, one marked with a “*”. Making the channel as described will require a 12-foot brake. Bob says if you aren’t able to find a 12-foot brake, a 10 or 8 foot piece would be better than nothing. If you shorten the length, be sure to center the stiffener around the wing strut attach point, since that’s where the stiffness is needed.