An update to my posts of several months ago regarding a tendency to drop a wing prematurely in spin approaches. I experimented with a couple type of wing fences. I initially thought they were helpful, but later concluded that I couldn't see a consistent improvement.
What did help was keeping the motor/props spinning in the approach: not much thrust, but it helped a lot!
As a disclaimer: my plane has a contra and I am flying at 5500ft altitude, so your results may not match mine
Dan