I ended up getting worried about not making it through the event in the allotted time after burning through 15+ breeding sessions with Blue x White and Blue/White x Blue/White/Stone, so I just purchased for gold.

Question for future Dragon Tales events - I feel like I remember seeing that the timer for completing the Tales didn't start until I started chapter 1. Is this correct? Meaning I could breed the needed dragon before even starting my timer for getting through the chapters?