In fact, yes I have worked on this. Since late October, I've managed to test it plenty of times, of which several times indoors. In the last race I was even using a 3mm thick wing (which I think don't have to explain sends most of the impact forces straight to the wing mounts)...
It's held up perfectly! Now I must make a comment take I also made TLR22 screw-type wing mounts for two cars, and last indoor race I saw a pair break. They were about 4-6 months old and held up well so far, but when the car was lying upside down on the straight someone ran into the car at full speed and both mounts snapped in two at the same spot. So they can break, but to be fair accidents of such caliber reduce the chance of survival of other parts on your car, too
Anyway, back to your question. I'm ordering 3D printed parts regularly, so just send me a PM and I'm sure I can include it in the next order.
Just a note on the one-piece wing mount I have now: It does not fit in an envelope, making postage expensive. Therefore I'll also be offering a two-piece version, which will be cheap to post (and a little cheaper to produce, too).