I don't think it's G-loads in a crash as much as the presure differential loading in a decompression in the lower decks bringing down the upperdeck and some of the wiring.
I'm interested in some of those who have flown the new F in the B747 for coments they had on some of the quirks I found,
Brand new retorofit with new fluffy rugs at your feet lost all the fluff and left large tufts behind under my socks in the first flight.
I couldn't manuever my way to get the 3 prong headset into its socket deep in the seat. I even tried sitting on the floor and it was impossible without a flashlight to even see.
and if you slide a 17 inch laptop into the side seat compartment don't plan on getting it out with your fingernails, use a fork and knife