I doubt it would damage the leather underneath but I honestly don't know. I think edging or glazing on this bag in particular is more cosmetic. I have seen really bad cracked edging on other leather bags before and it looks pretty ugly, so that's really why I hope it doesn't get worse. Overall, I still love my bag and I'm not going to worry too much about it. I would still recommend this bag and I think you should get a Cassie if you really want one.
Thank you for getting back to me! I think I'll get her next week and hope for the best.
Also, I remembered that I used Fiebing's Edge Kote on my LV key holder and it worked well for quite some time. Maybe that's an option for the Cassie, too.