Do 32u4's not work with this? (Pro Micro)

You need SLIPSerial.begin(115200); to start communication. In your code it is commented.
Did you use Nomad or a console?

I uncommented that line, and it still did not pick it up. I used nomad, as I have no console to test on at the moment.

Try to uncomment all the other lines, like on the original. I worked with an micro some years ago and I know that the board works with nomad, but not with console.

Still nothing. The diagnostics tab only shows EtcUsbDiscovery finding two devices upon plugging in the device. For clarification, I tried the USBtest sketch from the original repository, and even it did not show a connection to Nomad.

The strange part is that this board is just a smaller version of the Leonardo, even appearing as one in the Arduino IDE, and that board is confirmed to work in the CNMAT/OSC repo.

In general only Arduino UNO and MEGA are official supported, all other boards are maybe and depends on the OS and if there is a need of extra drivers. For increase power you should use a Teensy 3.x. The only difference between an UNO and a Micro is that the Micro have two pins (0, 1) more available and 500 Bytes more RAM.

In general only Arduino UNO and MEGA are official supported, all other boards are maybe and depends on the OS and if there is a need of extra drivers. For increase power you should use a Teensy 3.x. The only difference between an UNO and a Micro is that the Micro have two pins (0, 1) more available and 500 Bytes more RAM.