Hi
I also have a little "problem" with the fan (the setpoint for the temperature is very low so that the fan starts to cool like crazy even at low temperatures).
But I don't have any squeaking. But if you want the full power, then you also have the full noise level, which is definitely unbearable for me!

(No wonder when a HEPA filter (?) with such a high pressure drop is installed. An F9 filter would actually be enough here! Then you could also cool a bit more efficiently...)

Try running the projector in ECO mode and set the colour mode to "Natural". (Menu-->Picture-->Colour mode: Natural)(Menu-->Picture-->Power consumption: ECO).
With these settings, mine is always quite quiet because the beamer doesn't get as warm and the fan works less. Maybe this will help you for now.