Like has been said before, manufacturing defects happen. Doesn't mean they are bad products, it just happens. I guarantee Kifaru will back there stuff 110%.
I just got a pair of the First Lite Kanab 2.0 pants and the first time I wore them, the crotch blew out. I was gonna have my wife stitch them back up, but being the smart woman she is, she called them to make sure that sewing them wouldn't void any warranty coverage. We'll she was right. We sent them pics, told me to wear them through my Idaho hunt and then return them and they will replace them. So if it were me, I WOULD NOT have your pack frame sewn, as it may void the warranty for any future issues you may have.