OK, I finished epoxying the main spars with the 3.1 degree dihedral. I've been reminding myself this means I won't have that big "gluing the wing halves together" task later on because of this.

The angle looks good to me. To me, no dihedral on a shoulder wing plane makes the wings look like they are hanging down. This looks like enough to avoid that without making inverted flight too troublesome.

I pinned the spars down to hold them together on the first one. I tried clamping the second one as well, but I think the pins alone are fine.

Next step was stacking up all the laser cut ribs and knocking the burn off them.

The plans suggest creating a "custom" build table out of two sheets of plywood - one side propped up by six degrees.

I'm thinking I'll just build one half of the wing, then prop the other half up while I build the second half. This means sliding the ribs between the two main spars on the second half, but right now, that doesn't sound like a big problem.