Hello @jjgfromnj
An Edgerouter would typically be used as a router+firewall that creates a new "inner" network. Google WiFi is also typically used as a router+firewall that creates a new "inner" network. Connecting the primary Google WiFi to one of the LAN ports on an Edgerouter would result in an "inner inner" network (double NAT) for the devices connected to Google WiFi. If you also have wired devices connected directly to the Edgerouter, those devices will not be able to communicate with the devices on the Google WiFi network. Not just because they are on different subnets, but also because of the Google WiFi firewall that will block incoming connections.
It is possible to configure a single Google WiFi unit in bridge mode to avoid this, but you give up a number of features, including the mesh interconnect that supports connecting multiple Google WiFi units as coverage extenders, guest WiFi, and other features. Essentially, it becomes a relatively simple single WiFi access point, and I'm not sure it's worth the price.
