If you don’t find a custom solution to this I just wanted to point out that plugin is built by @r-a-y, one of the BuddyPress core developers. I expect it should still work fine. As always, try it on a test install before adding to your live site.
Thanks, I only needed to override the author name in blog post comments, so I searched for the related code in the plugin, modified it and added it to my functions.php in my child theme. Now the username is displayed instead of the full name 🙂