It's absurd, I've blocked outgoing connections for all home devices and appliances by default. The printer and TV were some of the worst culprits.

How do you watch streaming content? If you choose a movie in Netflix, I expect it makes an outgoing connection to Netflix's servers.

They typically use different dns domain and subdomains or subpaths, because the same server cannot ingest analytics and stream data at the same time. So, keep roku.com but block scribe.roku.com

I understand that. It would seem to take a lot of experimentation: Netflix has a lot of servers and domains, and at their scale many could be involved in any interaction.