One thing I can guarantee is that the wing is NOT flexing at the joiner.
The Wing root mates up to a fully epoxied Plywood box and 20mm CF joiner that is epoxied onto the wing spars and screws into the Ply box.
The wings flex fairly evenly along their length starting from around 150mm from the Pod.
I have run 50mm reinforcing tape along the top and bottom of the leading edge but I could definitely run another 50mm strip overlapping the edge of the first strip which would then cover around 90mm of the top & bottom of the wing.
But for now I’ll just try it as is with the new FC tuning and see how it goes.