It's just a quick and dirty remix because my old mount broke down and I just found multiconnect which I throw at everything I design now.
I just use the snaps from this collection: https://www.printables.com/model/716558-multiconnect-generic-connector-for-your-multiboard/files
hope it helps anyone, big thank you to Krobert for the neat base design and to David D for the Multiconnect :)
The author remixed this model.
I retraced the original model to fit the dimensions, removed the honeycomb connectors and added the Multiconnect rails to be able to connect this wall mount to my Multiboard.