Really interesting, this is the first time I hear anything about what is in those Realtek firmwares. Keylogger aside, is there anything fun or nefarious one could do with the radio?

Also, we use them at work in our products, and usually just get the firmware and driver binaries thrown over the wall by the board vendor, withouy any description or changelog. I'm tempted to throw a few different bins through Ghidra and see if I can tell what changed.