RACK IT 1000KG Mounting System

My design for mounting to the Bunnings RACK IT 1000KG shelving system. I have seen others do this but they all had their own flaws. Since I use this shelving system for my garage, workspace and 3D printing area I wanted an easy base for creating additional accessories, and this design was also to be able to easily print the designs up from the bed, without dealing with the key section being on top or requiring support material. The key/hook locks securely into the holes in the shelving system with minimal movement, easy installation and removal, and still offers substantial holding strength. I have included fusion files for anyone else wanting to create their own. This includes a sketch for the negative for keying into another component (including a 0.2mm tolerance). When extruding the negative cut I use 2.8mm deep with PETG, this will absorb the 2mm of the key, allow for any drooping overhang, and any additional room will only pull the key against the shelf locking it further. Example