It's pretty easy to add a new badge and manually (or automatically) assign it to people, but with the reporter badge I didn't originally consider that people might reasonably want to opt-out of having the badge. Adding that functionality is a bit more difficult. Maybe sometime in 2020.
Disclaimer: I am not a SMF expert
Could you implement this similar to how Copper Memberships are implemented? That is, once you reach x number of good reports, you have a 'paid' membership whose only changed permissions are the reporter badge. 'Wearing' the special membership would not affect the person's displayed title (unless this is an additional feature you wanted to offer).