The dupehammer is a good system. But when a gold badge holder closes a question, a comment still gets created on the voter's behalf, even though it will be immediately deleted by the system due to the question being closed as a duplicate. This is contrary to what normally happens when a moderator closes a question - no comment is ever created or deleted.
This is problematic because the comment's creation (even though it gets deleted in the same instant) still causes notifications to be sent out:
The owner of the question receives an inbox notification telling them that there is a new comment on their post, which doesn't actually exist anymore.
Anyone viewing the question at the time will be notified via web sockets that there is a new comment on the question, only to have nothing new at all load when they click to load the new comments.
I propose that all binding close votes refrain from leaving a comment, not only those cast by diamond moderators.