"A reasonable company would go after the manufacturers of fake chips, not the consumers who are most likely unaware they have a fake chip."
You go try to chase down random Chinese outfits pumping out fake chips.
Another issue with Z80/8080 instruction set, if I remember correctly, is that they are not orthogonal in regards to the registers. Some opcodes only work with registers B and C, others only with D and E, and so forth.
The ugliness of x86 instruction set has a long root.