First of all thank you for providing the PcbDoc files for all the DYI boards at:
https://github.com/m5stack/m5-structural-design-file/tree/master/PCB

I'd like to design some PCBs that slide into the ATOMIC and AtomHubProto DYI cases. The proto boards are good for a couple components but ideally I would like to design some more complex boards, possibly with SMT components to fit a more coplex design in the Atomic.

Unfortunately I can't justify buying the full Altium Designer program that loads PcbDoc files. Altium CircuitMaker is free though. However CircuitMaker does not load PcbDocs...

Ideally I'd like an Alltium CircuitMaker project that has the board dimensions and the Atom pin connectors, but nothing else. This would allow me and others to create custom PCBs easily.

Has anyone else gone in this direction, perhaps with another program?