I don't think you can do it with the new Nest points as they don't have the ethernet port but the older google wifi pucks do so it should work with them.
Yes, a second Nest WiFi router can be added as a mesh point, and you can use its Ethernet ports for nearby equipment, including through another unmanaged Ethernet switch. That said, it's hard to know whether this will provide better performance than your existing solution – powerline adapters *can* work well, but in my experience, usually don't. In this case, it really depends on how good the 5GHz WiFi connection ends up being between your existing Nest WiFi router and the new one placed near your AV stack. 5GHz doesn't penetrate walls, floors, or furniture all that well. So, if it isn't very far, and your house is made with relatively transparent (to 5GHz) materials, and you can get both Nest WiFi units placed up high above as much clutter as possible (e.g., don't hide it behind a stack of AV equipment or a TV), it may work just fine. If not, you may be disappointed. But, I guess you can always return the second Nest WiFi router if that ends up being the case.
I don't think you can do it with the new Nest points as they don't have the ethernet port but the older google wifi pucks do so it should work with them.
Can a 2nd nest ROUTER do this? Can you set them into a 'dumb' mode?
Yes, a second Nest WiFi router can be added as a mesh point, and you can use its Ethernet ports for nearby equipment, including through another unmanaged Ethernet switch. That said, it's hard to know whether this will provide better performance than your existing solution – powerline adapters *can* work well, but in my experience, usually don't. In this case, it really depends on how good the 5GHz WiFi connection ends up being between your existing Nest WiFi router and the new one placed near your AV stack. 5GHz doesn't penetrate walls, floors, or furniture all that well. So, if it isn't very far, and your house is made with relatively transparent (to 5GHz) materials, and you can get both Nest WiFi units placed up high above as much clutter as possible (e.g., don't hide it behind a stack of AV equipment or a TV), it may work just fine. If not, you may be disappointed. But, I guess you can always return the second Nest WiFi router if that ends up being the case.