Make S9 quiet (also with: NF-A12 industrialPPC-3000 (https://noctua.at/de/nf-f12-industrialppc-3000-pwm))
Remove standard Fan
Mount fan simulators or via firmware disable the "fancheck".
Here in this case, I have opted for the fan simulators because I operate the Noctua fan with an external power supply.
Finally, install the fan and you're done.
Test and observe temperatures.
That's it