I bought this XK3-Z8S-WZM Xbee mesh kit some time ago but didn't even think to buy cases. I have a 3D printer, a computer, and YouTube. So I did what any sane person would do and instead of spending $1.50 on a case, I spent about 8 hours learning the basics of Fusion 360 and designed my own.

The case is friction fit for both the board and lid. The hole for the antenna mount has slots for the alignment ‘pins’ along with an inner recess for the tabs to lock to. The hexagonal ventilation holes should keep heat buildup from being an issue.

No supports required.