Bonsai Winglet

I have a problem with the stability of my Bonsai during windy days. After reading a few articles it seems that it is caused by relatively weaker positive directional stabilization. It causes a type of aircraft motion called dutch roll (https://en.wikipedia.org/wiki/Dutch_roll).
I found some blog posts where people fixed that by changing a shape of winglets (https://www.rcgroups.com/forums/showthread.php?1606070-Bonsai-Setup/page21) so I designed a prototype of a bit smaller and longer ones.

In a picture is my first prototype. I used 10% infill and brim for a better stabilization for printing. It weights 21.2 g. That is quite heavy so I definitely will update the printing settings as well as the model aerodynamics in a future.

I will ad the flight test results soon.