I also started writing code for the Dynamic Bootloader present in the keyboard, but haven't made an attempt to implement code to flash a new firmware. Right now it can only be used to read memory.
Interestingly the firmware has a very simple default password - on my model i can unlock the keyboard entering 'vmcvmc' as Supervisor pin, regardless of what's set in the configuration.
I pushed the tool to github: https://github.com/funkenzuzzler/weytools