Patrick must have switched airfoils because I'm sure I've seen a semi-symmetric Blinkfoil also.
Thanks for posting those links Andrew..!
Instead of hacking out "diamond" foils, It's not much more work to make them properly curved.
Light and simple will still be the over riding theme with this plane.
One "trick I might do is assemble the frame on a pair of circular dowels that pass through the ribs, but cut in the 1/8" x 1/8" spruce spars after all the parts are "jigged" into place. Once the wood spars are installed, then slide the "jig dowels" out of there and admire the perfectly installed spruce spars.