This is the example I've just come across, but I have definitely run across many similar questions. A duplicate question should be thoroughly answered by an existing question. This question is asking about a rule that is a different rule with different wording than the 'duplicate' question.
An expert can look at the 'duplicate' question and infer that the rules interaction showcased there can (or could) also apply to Reaper and Twin Spell's interaction. A layman may not. In fact, having just interacted with a lot of beginner players, I would lay significant money that they would not 99% of the time. Likewise, someone searching for that specific interaction may not know to search for another, similar rules interaction to find an answer, especially if they are unfamiliar with the Stack Exchange site.
Why are questions about rules interactions that are in the same category as other rules interactions questions, but involve different rules or different interactions of those rules, marked as duplicate?