^ Dawn was already a giant at the start of Season 8 anyway. Also the Spike series is seemingly taking place concurrently with the last remaining IDW Angel issues, wherein Angel is not Twilight yet.
So I would say definitely before. Although the whole timeline of these comics seem very wonky, so hey I'll probably be disproven
I know that Dawn was already a giant, but Willow was away and only came back in #2 and then in #3 she is surprised that Dawn is a giant: "How come you're a giant?" So it has to be after the start of season 8.