If there is FIOS triple play, you have to keep the NVG468MQ active.
If client has no TV or phone service from Frontier you do not need to use the NVG468MQ.
You can just connect your router straight into the ONT and it should work.
Typical setup is like this
NVG468MQ -> FIOS Boxes (Cable TV boxes and phones)
-> Asus Router (This is essentially double NAT (Router behind a router))
First thing you have to do is disable WIFI.