In the early days of time sharing Dartmouth got a time sharing system working on a GE-225/DN-30. The hardware was upgraded to a GE-235/DN-30 system that was 3 times faster. It also had more instructions. So, of course, the person writing the GE-235 exec used these extra instructions.
Since this was all on an NFS grant, GE took the software and sold it to customers. But the software no longer worked on a GE-225. So they sold the customer a GE-235 with a wait loop in the exec to slow down the machine. This code was clearly marked. The customer was happy - they got what they wanted at the quoted price.
It was fairly common in the 1960's to ship a computer with many instructions disabled. For a price, wires were cut that disabled certain instructions.
The IBM 1401 had an instruction "read tape binary" that required extra money. But the diagnostics required this instruction so all 1401's had this instruction - paying extra money to enable this instruction caused no changes to the hardware.
We had a 407 accounting machine we used to list cards. It ran at 100 cards per minute. I noticed a couple of relays that were disabling every third cycle. removing this relay caused the machine to print at 150 cards per minute. I told this to the customer engineer and he said, "Yes, but you are paying for a 100 card per minute machine." So I left the relay in place.