Hacking Logitech Unifying | DC612 

thanks

Not yet. I still plan to though. I've put some work into porting my code over to QMK but that's about as far as I've gotten.

I disassembled the firmware and reversed it a little when I started this research back in 2018. Ghidra didn't exist at the time and I was far from an expert in reversing so I pursued other attack vectors instead. It's probably worth revisiting reversing the firmware. Firmware images are available on Logitech's github if anyone wants to give it a try.

This was very interesting, do you think your does the unifying reciever deliver the keystroke packets in a way that could be used to deliver packers for an alternat peripheral such as a game pad controller or mouse, or media remote?

Only mice and keyboards are supported as far as I'm aware. Although keyboards can send media keys like play, pause, stop, etc...