I'm looking at Eero as an example. I noticed that some mesh routers are tri-band, and the extenders are dual-band. Can someone explain why you would want to extend your network with only dual-band instead of tri-band? I thought the tri-band helps speed up the network and you would want that everywhere. If the extender can't receive the third band then why bother? Seems like the product descriptions don't explain this part very well. Thanks.