Invisible Parametric Shelf Attachment System

This is a proof of concept for a minimally invasive (but rock-stable), modular/parametric system to attach stuff to wood boards.

It's using two hidden dowel pins secured with 3mm SPAX wood screws. I'm planning to use this in my campervan, so everything should be removable & tight fit (no rattling or shaking loose, and I want to be able to easily adjust/swap any shelves later on). To this end, the receiving part can be scaled in the Openscad file ("fitting test"). My test prints are PLA on a poorly calibrated printer and x1.07 scaling gave a perfect&solid fit (removal of the example shelf shown requires gentle tapping on the underside with a hammer).

The included simple shelf is parametric, and I just might eventually add other stuff. There's also a jig for the shelf (drill hole positions must be very exact or it won't fit). The picture shows a quick test print I made with PLA (ultimately I'll use ASA). Feel free to play around with it.