In my area, not even the Comcast installers like the Comcast routers. Usually, you can talk someone into setting the modem/router into bridge mode. With some models the customer can do this and if you are lucky, the hotspot will shut down in bridge mode. In one commercial installation, Comcast installed a modem for the Internet connection and another for the hot spot. We couldn't elect out of the hotspot, but after the installer left, I decided that I was one power outlet short and the hotspot drew the short straw.

By the way 3.1 is the latest spec, but it is not generally available and is being rolled out in test areas.