factory reset = set the system back to the way is was when it left the factory, but the FW will still be the same as it was when you did factory reset
on 9.2 factory reset it will still be 9.2
on 9.9 factory reset it will still be 9.9
factory reset will NOT downgrade
factory reset just set everything back to the default setting, powered on after a factory reset, it will be like when you 1st turn on the system