I assume that has to do with restrictions where you live? Otherwise you could just use clearnet again, once you've used clearnet on an account, switching to Tor doesn't hide your identity.
Does the forum store all IP addresses from the first day someone created an account on this forum? So anyone who has ever accessed a forum with their real IP address makes no sense to use Tor at all? I know there is Limit IP retention as an option in the profile, some interesting information can be found there.
Retention/privacy infoAbout privacy