I know that someone (can't find the post) suggested using an extension on the top winglet as support for the static load test, but still allow the wing to flex when subjected to the aero pressure. I think this is what Ferrari are doing with their little metallic extension they've had the last few races (click for high res):
If the test is done with a perpendicular load, I think this support will keep the wing from flexing. But see that it is attached (and I don't think its firmly attached, just floating) right on the edge of the black adjuster. With the aero-loads the wing will bend sideways (endplates will move away) and the support won't stop the flexing anymore.
The metallic extension looks aero-neutral to me and shouldn't be a flow conditioner since it is the first thing to hit the air so it shouldn't need "conditioning".
What do you think?
Edit: Or maybe not.. here is another view of it, if you click it to view high res you can see that it is actually entering the support there, not just floating. It should still allow pivoting though..