I was worried about burn in, but after hundreds of hours of Zelda, Fae Farm, which do have static UI elements, I still haven't noticed anything.
I haven't connected it so far.
I use homeassistant a lot, but haven't connected the TV yet.
From looking at the integration, at least its not cloud bs, so I could probably block everything to and from the TV except TCP 3000-3001 with homeassistant and it could still talk locally with hass.
I've already blocked LG's ads domains, just in case I ever decide to plug it in, but denying everything except homeassistant would be nice.