Living in Hawaii, where we have to send most of our crap via airplane, unless you can afford 1-2 months on a ship wait time. I'd be a bit worried shipping my iphone 7 back hoping that my iphone didn't catch fire burning up the plane and killing the fedex pilots.
That being said, maybe we should drain our batteries down as much as possible before shipping? If it did catch fire, it would burn less than a full charge.
Note7: I deliberately replaced X brand since any li-ion battery can catch fire if hot enough or enough pressure is placed on them. Samsung, and I give them credit was just doing what "WE ASKED THEM TO DO!" make our phones last longer per charge. They were pushing the envelope and got burned.