Jack Erbes is one of the modern day geniuses of foamy construction. Here's his RCG build log of a KFM3 wing for the Blu Baby. My BB32 wings broke in half, so I'm especially interested in this. I'll lightly edit, but the first person voice is Jack's. I'll try this later and do my own writeup if I think it might be useful. Jack writes:
I recently made a KFm2 wing with polyhedral tips for use on my KFoenix Stick and flew it in RET configuration (Rubber, Elevator, & Throttle, no ailerons) and was really impressed with it. It had excellent tracking and control and good rudder authority, which had been a problem with the stock Slow Stick wings. The wing seem to "lean into" the turns nicely as speed increased and as turns were made more aggressively. It was almost as if I were flying a wing with ailerons.