Some experimental evidence ...
I never enable wi-fi on any of my devices but I have always made a note of serial number and MAC address as one of the first things I do with a new device. My most recent purchase was the KA1 at launch time. MAC address was visible at that time.
Now here's a mystery, something changed during the course of me composing this post. The KA1 went into standby whilst the Device Info page was displayed. When I used the button to switch it back on again the MAC address was now visible. So I let all the devices go into standby before switching them back on.
The current situation for each of my devices, on the Settings Device Info page is:
Glo - fw 4.6.10075 - MAC is NOT visible
AuraHD - fw 3.19.5761 - MAC visible and correct
Aura6" - fw 4.6.10075 - MAC is NOT visible
H2O v1 - fw 4.7.10413 - MAC visible, but wrong value!
GloHD - fw 4.7.10413 -
MAC is NOT visible now IS visible but wrong value!
AuraOne - fw 4.7.10413 -
MAC is NOT visible now IS visible and correct.
The 2 devices displaying a wrong MAC address are showing the same wrong value (00:90:4C:11:22:33) which I think must be some dummy value as it doesn't match any of my devices.
Clear as mud!!!
