If we do, we will reach out to them first with any concerns and then make another post here prior to blocking them.
Based on the time stamps, it does look like the same person made 17 accounts on ttrpg.network on December 8th before going back to making them on lemmy.org. Running a more robust query, in total I'm seeing 88 of those accounts on lemmy.org and the 17 accounts on ttrpg.network, all of which are banned on here.
Right now I'm thinking that we will keep an eye out for more accounts, and then reach out to admins if it becomes a problem on another instance