User posts a poor quality question that is put on hold.
Rather than edit the original question (or read the rules) they post one or more new questions that are essentially the same.
Those all get closed as a duplicate of the first question.
The problem is that the original gets deleted by the Roomba but the other's don't because they are closed as duplicates. As mentioned in answers to the above question one alternative is to close with a different reason but that would need quite a bit of a culture change and I've noticed most diamond mods go down the duplicate path as well.
On smaller sites there's often a lack of users than can / do cast delete votes so I'd like to propose a change so that the Roomba would still go ahead and delete when other criteria are met and the question is a duplicate of another by the same user. For that matter I'm not sure that the same user check is needed, maybe duplicates of any deleted question should go because they tend to be annoying dead-ends when you find one.