Definitely a good start but in a targeted attack scenario that's pretty trivial to bypass, if someone brags about having the latest Das Keyboard or something that's all it'd take... we need cryptographic authentication in the USB specification or at least a randomized serial that'd be unique per device so an attacker would need physical access to clone your keyboard.

I believe modern Thunderbolt already has this sort of cryptographic device authentication, which means not only physical access but at least a bit of reverse engineering skill, a much higher barrier than knowing their keyboard model.