So because you are using a firmware from bitmain, setting your gear to 16.5th is NOT overclocking? it literally says hashrate +2th. Also if we were to define "stock firmware" as the firmware that comes with the miner by default then your statement is not accurate, the firmware came out around mid 2019 and by then Bitmain never sold any Antminer S9i, you have manually upgraded the firmware, but that does not matter, there is no Antminer S9i that is labeled as 16th. If you agree with how OP describes his miner then you should be fine with people advertising their S9 19th because you can get that hasharte of an Antminer S9i 14.5th using a custom firmware.
nope not saying that at all - just saying that it is not misleading to say its 16 th/s - I was just saying that it can be achieved with official firmware vs some random custom firmware from who knows where. I agree that the miner is still just a 14.5 and yes it is over-clocking.