Idk what a forum update would change if you wasn't running an old beta version, which I assume wasn't the case.
Xenforo has lots of antispam features and have had for quite some time now, you should consider putting them to use as the spam has obviously not stopped.
With that said I'm done reporting posts for spam for a several reasons.
1) There's a cooldown. Usually there's lots of spam being posted in bulk.
I won't sit here and wait for that cooldown before I can report yet another bot account.
2) There's settings in xenforo to avoid this. For example don't let new people post link, require X days membership and post count, and blacklist the sites they're linking too.
Relying on your users to report stuff is a bit too much to ask for imo when all you have to do is to toggle an option on.
Staff is nowhere to be found during weekends. I've reported posts/accounts before that was still online several days later. It feels pointless.
Get a few more mods. Or assign a handful of trusted members as semi-mods that can view report tickets and temporarily hide reported threads/posts from the public until a staff member has resolved the ticket.