Just an FYI.
I set this up exactly how it is listed with the add-on. Thought I was doing really well with spam because I hadn't had to remove any in several days.
Then, I set up the brave browser to see how it worked. Checked the settings and it uses TOR. I was thinking about removing that in case there is an increase in people using this browser, but decided to go try to register first. Sure enough, it blocked me on the brave browser.
Out of curiosity, I hit the register link on chrome, firefox, and Edge. I was blocked from registering on all those browsers as well.
After further review (been too busy to check this lately), I have had zero registrations since adding this to cloudflare, and about 500 blocked registrations. My current IP addresses this evening are included in the blocks IP's.