I have used it on a Legacy 40 wing. Found it very user friendly. After building the two wings to include leading edge  sheeting, put them back on the jig with the middle of the tubes centered in the center of the wing. This keeps the two halves in alignment. The outer 6" or so will be outside of the jig, unsupported. That's OK. Glue the two halves together and slip the tubes out. You now have a complete one piece wing. Mount the bellcrank in any of the usual ways. I made top and bottom mounts and mounted it in the so-called floating style. As far as the two piece wing, most free-flight and many R/C designed are constructed this way so it is not unusual.

Join them the same way you would if you were making a one piece wing that was joined in the middle. Once both wings are threaded onto the rods, that is essentially what you have.

Thanks for the comments. I must add that I'm concerned about strength in the trailing edge with two completely separate wing panels.

While I don't have a set of ribs to suit at present, having played around with mine, I think I will use 3/4" fold back clips to hold things together rather than the supplied clothes pegs. The clips are stronger and you can fold the arms out of the way. Much less vulnerable during the early stages of setup.

All my wings are built in two panels, on 1/4" rods.  Joining, you just match the spars, L.E. and T.E.  Butt joints are not strong, so plywood plates are put on spars, L.E. and T.E.

If the wing has dihedral, block up one panel, sand the spars to meet, and proceed as before.

Floyd