Technically, S&W can and would get you a prepaid label for Fedex, but I didn't want to deal with all the headaches at Fedex Office, return shipping, etc. S&W will work directly with FFL and get them prepaid label for warranty work. At least my FFL (Elite Armory Castro Valley, where I got the BG2.0 from) is not charging me anything, and handling the sending and receiving for me. I'll be just out for DROS cost if S&W ends up replacing the frame, however.
Just for the record, the crack/seam is virtually undetectable from the outside, and I wouldn't ding my FFL for not catching this (or myself, really, when I was buying). It is on S&W QC for sure, but I'll wait and see how their support/warranty handles this.