On the contrary, We are slowly but surely building up a thorough documentation to make it easier for developers and also releasing the necessary files for development. In uiflow we have added the custom blocks function so third party developers can create easy to use blocks for their compatible hardware, this is in it's early stages but will become more feature rich as time goes on.
I intend to do a video series on how to go from a proto board to getting your module fabbed by a pcb house. Some of our Japanese users have already developed their own midi module for the device and are selling it commercially https://necobit.com/denshi/m5stackmidimodulefamicomsynth/ and another Japanese user developed a usb host module.
Suggestions on how we can better facilitate this process are more than welcome.