Very soon after, I found this post in search of a better duplicate target. But a gold badger had already gone through and marked the question as a duplicate of my original nomination while I was looking for the later one.
I tried @ing the gold badger but they didn't comment so I suppose that doesn't ping their notifications.
So, what's the appropriate course of action here? Should I nominate it for reopening because the duplicate target isn't valid as such? Should I flag it for moderator attention with the proper duplicate question? Should I look for a comment from the gold badger so I can @ them back to the post in question?