I disagree those are the only options.

For one, I still have yet to see that ignoring can actually work. It never did in forums I used to frequent. People who crave attention will up the ante until they get it one way or another. To sociopaths, negative attention is better than positive attention because it's free and easy to obtain in large quantities.

What I have seen work is not heavy moderation but highly selective moderation. Target the root cause troublemakers, who are usually low in number but attract large followers when they are allowed to persist. Ban them, and when they create another account, ban them again. Eventually they will find a forum where there is no moderation.

They're like locusts, even in small numbers. They invade, disrupt, and leave chaos in their wake. Soft moderation is useless when it comes to these types.