I have my Samsung TV wired to my network only for remote control with Home Assistant (can turn it off if nothing is playing for example). But I force all of its DNS to use a pihole, blocking all Samsung domains. I think I also have firewall rules to also block all internet access on it except NTP, but I don't remember if I still have that enabled or not (there may have been an issue with it disabling something that I needed for Home Assistant to talk to it).