Building one now and I too would like some more details on the build. I took up archery last year so I have some arrow shafts on hand. They're 8mm shafts, however, so I had to modify the parts with bigger holes.
I am guessing, based on crude measurements taken against the video, that the front wing brace is 100mm from the front of the arrow shaft. You can use the front brace to set dihedral. The servo mount goes between the wings (there are guide holes for the wires in the rear mount.
The 4 channel option has a third servo mounted on top. As this is under the wings, my assumption is that this server uses opposing arms to operate ailerons on the wings.
These servo mounts are sized for 5g Servos.
As for the arc of the airfoil? I'm going to guess that the center section (there are 5 sections to the wing), is 2 or 3 layers of foam above the build surface.
Also note that the front wing brace has holes at the bottom for 1.59mm wire to be used for landing gear.
FT is probably working on a build video for this, I would assume.