I have a strong, but not necessarily logical antipathy to cmake. In the past, as a user, I’ve found it very, very difficult to work with.
Arduino does support many, many different hardware platforms and provides a fairly nice abstraction that makes dealing with it as a user very straightforward. The Planck and ErgoDox EZ are just as ‘Arduino’-friendly as the Model 01. When we talk about “Arduino”, we mean some subset of the build infrastructure, the bootloader, the IDE, the standardized tool chain, and the ‘arduino core’ that exports the primitives and runloop we use.
I don’t plan for Kaleidoscope to move away from the Arduino runloop, the Arduino core, or being buildable in the Arduino IDE or with the Arduino toolchain.
I believe I saw some discussion on the Arduino developers’ mailing list in the past few weeks about linking to libraries built using other build systems. That may be worth taking a look at.
That being said, I’m very excited to see your first bits of test infrastructure taking shape!