Hi, if the difference is really just 1mm in height, wouldn’t it be possible to just lay a 1mm high piece of plastic in an existing cage? Fasten it with glue if needed.

Hi, from my experience watching beekeeper videos on YouTube - that queens/bee cage is made of plastic or similar not beeswax. Wax would melt too easily and does not have the mechanical strength to stop a bee from breaking out. As for 3D printing wax - it should be possible by just lowering the temperature of the 3D printer (if you can somehow modify the supply), and then you should be able to print what you want - candles come to mind.