I've played that combination certainly more than 100 times on mtgo, but i wish to know exactly what happens. I know how it starts
cast HUF, bonus round trigger -> resolves -> copy resolves revealing spells 1-4. They go on the stack at the exact same time, but i get to chose the order. But what about the bonus round triggers of those 4 cards, are they in an determined order or do i get to chose that order as well?
So the stack is
HUF original - 1 - 2 - 3 - 4 and now 4 bonus round triggers go on the stack as well, on mtgo it seems like they go on the reverse order, so the stack is
HUF original - 1 - 2 - 3 - 4 - 4c - 3c - 2c - 1c
But that seems really strange to me? 99.9% of the time the order does not matter at all, but i wish to understand what really happens and why.