The forum's logging shows the new rules that block new user registrations from ASN 45609 are being triggered, one of them only 12 minutes ago and the other a few hours ago. Impossible to know if it's blocking legitimate new users or the same spammer trying over and over to get back in.
But at least so far we're not blocking all registered and unregistered people from simply viewing the forum. A complete block would shut out everyone in India connecting via this large telco. We had that with vbulletin. I regularly heard complaints by email and social media. Really hoping we don't have to return to completely blocking almost all access to India again.
Regarding all the questions about whether certain forum behaviors are possible, I don't know. Unless the problem returns and can't be blocked, I'm not looking to dive into the forum config again. But if anyone wants to read the xenforo documentation and point to specific features, that would be the path to make these sorts of suggestions. Now that Teardown is over, I'm getting back to a final sprint to wrap up my contribution to the Ornament and Crime project, and then I'm planning to spend a few weeks merging lots of contributions and try to fix a few a few more bugs for a first 1.60 beta. Every time I get into forum config it turns into quite a distraction and right now I really want to get O_C wrapped up and 1.60 started.