Confirmed to be working on Antminer S9SE !! I really have no idea why did I only include S9k in this topic, although I have tried it on S9e and it worked, anyway, now that you mentioned it, I have edited the title and included S9e.
Make sure to save settings and reboot system afterwards. It will still boot up at 100% fan speed but will decrease according to configuration once it starts mining (about 6mins in the S9SE case)
Rebooting the system is not required to save the setting, it's only important to actually activate the settings, as for the 100% during the boot, it's normal and an important procedure to confirm that the fans can actually hit x RPM.