So, I figured I'd take the effort to sign up with a disposable email to see if stuff worked with that.
It does seem to. You might want to look into restricting the use of temporary emails, as it's a potential source of abuse.
There is an issue in the sign up process, however! The 2FA will email you telling you that an IP attempted to log into your account. And tell you this IP address. However, the IP address it's giving is the local address of the server hosting the forums. Not the external address of the person trying to login to the account.
I'd rather not post the IP in question, so, if you need more info, I'll DM You a screenshot of the email.
On the greater community issues of the forums, there is an elephant in the room. I understand you'd rather focus on the technical side of things. So, consider this a side note for the time being.
The Moderation of The Escapist was.. Infamous. There were news articles for how flubbed the past (And some present) moderators handled some issues which cropped up in the past. There are a number of people who received harassment and abuse from moderators past and present. To see the forums with the same mod team, the same rules and an even shorter allowance for mistakes will put a number of people off.
You seem to have a different attitude, and I hope it's cause for optimism. I wish you all the best with the new forums!