On the website I am working on, we are seriously concerned about comment author privacy. We do not want anonymous comments per se. But we also do not want the full name of the author to show when they make a comment. We would much prefer only the first name of the commenter or a nickname.
Please, how do we ensure that only the first name or a nickname of the comment author shows up when they post a comment?
wpForo is a forum plugin not a comment plugin. Are you sure you're talking about the wpForo plugin? Our comment plugin name is the wpDiscuz: https://wpdiscuz.com/
In case you're referring to wpForo, please read this topic to see what wpForo shows, it doesn't show First name or last name, it only shows Display Name and the nickname. Both are available for users to manage and change: https://wpforo.com/community/faq/nickname-vs-username-vs-display-names/