@westborn Just looked at your new modem. The SB8200 has two ethernet ports, one will go to streamer, other to remote control device. Most likely you're going to have to use a laptop as this device, and it must have ethernet port, everything hard wired, don't need wifi at all. The laptop will be provided permanent IP adress. Very unlikely your tablet has ethernet port, extremely limited number do. Not all laptops have this provision as well, in which case use usb to ethernet port conversion device. You don't have to worry about wifi with this setup.
Telephony or having telephone connected to modems is another concern because of contamination/ noise. Don't connect phone to modem, most ISP have dedicated phone modems, just have to ask.
I purchased an enterprise level managed router couple months ago, has NO wifi capability. My intention is to experiment with completely isolating audio system from wifi contamination. I have Trifield meter which measures emi in form of rfi, wifi capable routers are one of the richest rfi environments, read noisy components connecting to our audio systems. With the managed router, wifi can be segregated to separate branch.
Keep us informed, will be interested to hear your outcome in regard to sound qualily.