And you can even have pretty easily wifi LEDs in R7800, as long as you accept that the original wifi LEDs can't yet be used (as they are only visible to the OEM firmware).
I use myself the two unused LEDs on the right that on the "wifi enable" and "wps" buttons. They can work easily as wifi LEDs. Just add this to your /etc/config/system:
config led 'led_wlan2g'
option name 'WLAN 2G'
option sysfs 'r7800:white:wifi'
option trigger 'phy1tpt'
config led 'led_wlan5g'
option name 'WLAN 5G'
option sysfs 'r7800:white:wps'
option trigger 'phy0tpt'
Or you can automate that settings in the LED detection phase like described in Netgear R7800 exploration (IPQ8065, QCA9984) - #6 by hnyman