One of the things I do not like about blocking policy is that there's no way to apologize. If you get into an argument with someone, get blocked, and realize later you were in the wrong, there's no way to seek forgiveness from that person.
Take ~Kaxen6 (https://www.deviantart.com/kaxen6) for example, an artist I used to watch. She and I got into an argument over... I think it was zombie movies. I like them, she didn't, and I attempted to push my opinion. Too strongly, as it turned out, because next thing I knew she blocked me.
Not that I think trolls need another loophole to keep trolling, but it would be nice to have a way to say "I'm sorry".