Can I still use the built in Circle on my Nighthawk if I am no longer using it as my main router?

I am considering switching to a different router. I currently have a X6 R8000. It has Circle built in. If I replace the router with something else, can I connect my Nighthawk somewhere else on my network and use it as a switch with Circle built in? Would this cover my entire network still? Even though the traffic is no longer going through the Nighthawk? I am asking because I want to go to a much more robust system like Ubiquiti Unifi, but my wife loves the Circle app. I know that I can filter things with OpenDNS, but with Circle it is super easy to pause and unpause devices as needed.