Maybe this has been brought up before, but the wing slot in the FT duster fuselage is considerably undersized, and does not take into consideration the linkage stoppers. I adjusted the slot myself with marginal success, but I do think it is something flite test should correct.
So far from flite test I have scratch built the Tiny Trainer, Fokker DR1, Simple Soarer, Mini Sportster, Mini Scout, and FT Duster. The FT Duster has been my least favorite build, and I think it is because it is an earlier design, and I found things just did not flow during the construction. I hope they revamp the FT duster in the near future.