Hinterher.com Drawbar Storage

I have built for myself a bike trailer out of hinterher.com parts. Parts that are not available by suppliers I design on my own. So the Drawbar storage parts.
They are bolted to the frame with M3x12 countersunk screws, see drawing. After printing the parts, I add M3 nuts via the horizontal slots to the parts. The parts are printed in PLA, cause when they brake I can easily reprint them.