Oh, this the exact use case for a tool that I’m writing right now! It’s a daemon that runs on the gateway and acts as a DNS + DHCP + Firewall to monitor the activity of IoT devices.
https://github.com/mafik/gatekeeper
In the 1.6 (expected next weekend) I’m adding traffic graphs for each device and remote domain that it talks to.
This restriction is meant to protect high definition content from being ripped by pirates. Open systems don’t offer the same DRM guarantees as the locked ones.