There is no "advantage" to ignore. You cannot post on that person's threads if they have you on ignore, whether you agree with them, disagree with them or anything in between. The person can put 82,000 people on ignore but then no one at all will respond to their posts, plural, no matter the subject. If their beloved pet dies you won't be able to tell them you are sorry for their loss.

It has nothing to do with whether they do/do not like opposing points of view and why would you want to be oppositional to a person who you believe (it may not be why they have you on ignore) does not want to hear it? That's a waste of your time! If you have something to say about a subject, start your own post and say it. Other people are not starting posts so we can give our opinions, they are asking for help for themselves, or support, etc., not to be a forum for what someone else may need/want.