depends who you're trying to thwart TV downloading updates? it'll probably work trying to stop MS from spying on you? they have engineered parts of the stack

depends who you're trying to thwart TV downloading updates? it'll probably work trying to stop MS from spying on you? they have engineered parts of the stack to avoid things like firewall and hosts file blocks, so presumably they have an IP hardcoded in case you block all their hostnames at the DNS level