The worst part is that spam posts all make to the RSS feed, my primary summary for Echo JS. So yes for every action that could mitigate this.
I would have contributed to new features for this forum, but the irony of a JavaScript community on a Ruby platform is concrete, and I don't know Ruby ¯\_(ツ)_/¯
But there *are* cases where something more could have be done. Spam posts were prompt removed, but spammers weren't banned. As you said, new account could be easily created, but it's still a nuisance, even for them.