Upper case letters work in the “Internet Status GUI”
So far, only the Factory default MAC works with lower case. or at least is shown as such in the menu.
Kernel Log
[ 2375.090000] device wlan0 left promiscuous mode
[ 2375.090000] br-lan: port 2(wlan0) entered disabled state
[ 2376.900000] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[ 2376.920000] device wlan0 entered promiscuous mode
[ 2376.920000] br-lan: port 2(wlan0) entered forwarding state
[ 2376.930000] br-lan: port 2(wlan0) entered forwarding state
[ 2377.310000] br-lan: port 2(wlan0) entered disabled state
[ 2377.410000] br-lan: port 2(wlan0) entered forwarding state
[ 2377.410000] br-lan: port 2(wlan0) entered forwarding state
[ 2377.420000] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[ 2379.410000] br-lan: port 2(wlan0) entered forwarding state
[ 2387.720000] device wlan0 left promiscuous mode
[ 2387.720000] br-lan: port 2(wlan0) entered disabled state
[ 2388.210000] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[ 2388.220000] device wlan0 entered promiscuous mode
[ 2388.220000] br-lan: port 2(wlan0) entered forwarding state
[ 2388.230000] br-lan: port 2(wlan0) entered forwarding state
[ 2388.460000] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[ 2390.230000] br-lan: port 2(wlan0) entered forwarding state
[ 2412.200000] device wlan0 left promiscuous mode
[ 2412.200000] br-lan: port 2(wlan0) entered disabled state