Hello, I find that we are relatively well equipped to detect them AQB has done excellent for this and if I understand you correctly, your problem is not detection, but just preventing them from coming back? Then there on the other hand we have nothing. On Dolphin, we had Stop Spam Forum which integrated the database and prevented registration, we see it on UNA but it does not act that way yet but a ticket has been opened here on this subject, it will already be a very good thing.

In fact I had already raised the issue in this discussion.

My idea was to use the Twilio module because a new phone number is difficult to obtain. We could have kept it in a table as a blacklist and not authorized a new registration if the number is present in this table. Maybe you can leave a review on this idea?
I had also explained that using Twilio without this possibility would cost me a fortune if spammers were allowed to come back constantly with the same number. That's why I don't use it.
Looks like you can understand me?