I wouldn’t remove the network card. That also kills the Bluetooth remote.

It's a sacrifice I'm willing to make.

Unplugging it from ethernet/wifi may also not be enough. If it’s connected via HDMI-HEC, it could get Ethernet over HDMI.

This is why it's unplugged from power until I can properly control it without compromise. If that means I rip out the hardware in favor of some generic "is just an HDMI receiver with an LG display attached", then so be it. Or it goes in the trash. IDK yet.

LG doesn’t specifically list HEC support, but at this point, I’m not sure they can be trusted.

Model # 65UT8000AUA, which is rootable. I already rooted it though 😂

Safest path is to block its IP addresses at router level, unplug it from ethernet, factory reset it

Yep. I blocked it on my UDM. I don't think it even has an ethernet port, now that I think about it... I should check.

only go through a trusted streaming device without HEC support, block all the LG servers at router level

The only thing plugged into it is an Apple TV. And we rarely use it these days. I do run Pihole on my network, but admittedly I haven't kept track of the shit coming out of the TV.

and power the TV down when not in use

They do this even when "turned off". That's why it's unplugged.