There's a pretty consistent fact about dealing with trolls...almost all trolls eventually get bored and leave. The amount of effort required to continually evade bans only for their posts to be summarily deleted with very little reach just isn't worth what little attention they get. The asymmetry between the effort required for a moderator to nuke their post and account (a couple clicks) and the effort required to evade moderation helps a lot here. Even the community just needs six red flags (see the "What effects do these flags have on a post?" section of this answer) to remove any post and alert the system of what the user's up to.
I can count on one hand the number of trolls (plus another hand if you count spammers) determined enough to keep posting after any non-trivial amount of time with all of their posts getting removed.
Thus, there generally isn't a need for anything special. If a troll is determined enough to get on that list of a handful of people, they eventually become known to community managers who make sure that all of their posts are removed from the network (obviously not going to name any such trolls, because, well, feeding trolls is bad).