I almost forgot to show this part. The plans call for 4 of these plywood bridges at the wing root. I believe they were for strength where the rubber bands curve around to attach at the LE (the TE is hardwood in the center).

I thought about not putting them in, but then realized that for the LE dowels, they would have no internal support, just where they glued at the LE. Soooo, I'm going to put a shear web between these pieces, which will give the dowel some purchase at the rear.