I do this and it's been somewhat useful - you need to disable blackhole rules periodically to get app updates though (and the TV will send a storm of DNS queries your way if you dare to block queries)
Frustratingly, recently the latest Plex app stopped working with the block rules I had in place, so I've had to allow through a lot more of the TV's traffic to samsung domains than I'd like.
My primary annoyance is Samsung's monitoring of what I do on my TV, and secondarily their IPTV service, which it seems to default to on startup (I only use apps and PC/game console sources, the TV isn't plugged into or tuned for any channels).
Realistically I need to switch to a Shield TV and hope that nVidia's privacy policies are better... and never buy a samsung tv ever again.
i tried blocking DNS or whitelisting and you probably see that large amount of blocked requests because it tries like every second if you refuse the response.
I mean, normal TV it's 90% ads 10% content, do we need to watch even more ads?
Anyone has any idea on how adding a filter like AdBlocker to your router? Never thought about this but it's getting useful af.