I'm using Pi Zero 2 W with a flipped case but i realized that Pi gets hot inside the enclosure. This duct will provide air circulation around the Einsy board and the Pi.
I printed using PLA. PETG works too.
0.2mm Layer Height
15% Density
You can download the remix flipped Einsy case from here:
https://www.printables.com/model/155380-einsy-case-raspberry-zero-2-w-flipped
The author remixed this model.