Despite reboot is required, no alarm is shown in System Health.
Good point. This issue must be that if you enable it in FMS without reboot you don't get health alarms.
My testing shows that if you enable the module manually that you get the normal "BOOT" and "?" health alarms turning red.
Yes it is true for any change in HwSettings - it will bring up BOOT alarm due to very crude memcmp() over HwSettings data .