Foxwell NT650 Elite Odometer / Mileage Function is not to read and write odometer value. This function allows the car to recognize the new dashboard after replacing the old one (because the old one is damaged), that is to initialize Odometer Instrument Cluster (reboot instrument cluster parameters after replacing new instrument panel). So far, it covers Infiniti, Nissan, Opel, Vauxhall etc.
As you can see in the following image, Foxwell NT650 Elite covers 25 special functions and "Odometer" is listed in middle.
In order to help all you understand this feature " initialize Odometer Instrument Cluster", foxwelltool.com engineer took a set of photos and a video: