Here the scoop.
Zagi tape is nice. But its not nearly as crash resistence as polyester or ripstop. It holds the wing together in mid airs and crashes.
The bat wing is a modified 479. The picture you are refering to is my SSC mini choker from the "Louisville slugfeast". The wing did have anhedral. Mike doesn't cut in the dihedral. You can do it yourself. They seam to fly the same. The curve part of the wing is on top and the flat on the bottom.
Ron