Yes, even Professor Sakata used biochemical means to effect his mutations. Besides, how do we know that Golgom's power isn't technological in nature? Just maybe carbon based instead...
Also, the term for the KRs is "kaizo ningen", which if I understand correctly means something like "customized human". I remember a marvel comics role playing game where a class of hero is "altered human" which means he was normal but turned into superpowered form by radiation, chemical means, whatever. The game distinguished between altered humans and high-tech wonders but if a guy is cyborgized, I guess he is a combination high-tech wonder/altered human, as opposed to Iron Man who is pure high tech wonder... (unless of course you count his heart as a cyborg part...)