UA's F seats have what is called a lap and stash seat belt, different from a three-point and five-point harness. "Lap and stash" is when the lap belt is separate from the shoulder belt. My first car, senior in HS, '88 SAAB Turbo 900, had this - the automatic stash would come across my shoulder when I would close the door, I hated it, even though the car was beautiful.

I digress, sorry - on UA, it's the first time I have seen any kind of belt other than a lap belt on a commercial a/c for passengers.

SQ F and EK F have ample space around, more than UA's F. But it's safety first for TODs and UA F passengers! SQ has a padding on their lap seat belts (thought I'd share that with you). On private planes, most have the three point harness and the lap and stash seat belts.