I love how literally nobody is answering your actual question.
I agree that this is problematic and we need TV reviews to include at least some of the information you cite.
If it helps, I have an LG smart TV. It complains if you don't let it access the internet at setup, but if you connect it once and let it do its initial patching, you can decline all agreements and not get nagged until it tries to update again. To keep it from further updates, you can disconnect it from wifi and it doesn't seem to try to reconnect. I can't speak to public wifi because there aren't any open access points near my TV.
In contrast, I have a samsung TV that loses its mind if it can't connect to the internet and becomes basically useless for all the nagging.