I'm going to need to gem speed to finish. I started on day 1 and lost a lot of time waiting for petals, despite buying two packs and sending adventures every two hours. I bought the extra pearl pack and then received two from adventures in the last day, but it left me with 10 crystals to get and 7 hours left to complete the final stage of ch 10. I got 7 crystals from 4 pearls, and am now waiting four hours until I can collect again. That will leave me needing to speed the making of the final emblem within the remaining time.
Even spending to buy the packs relatively early on gave minimal advantage, which is a bit unfair. I am prepared to spend a bit, but the event was designed to require significant investment from most players it seems.