Why not just a post up your butt and then you can stick the passengers in the floor like a pin cushion? Less passenger space and seats = more freight space.
I ought to patent that.
On the plus side when your neighbor pukes it will just flow straight down to the floor and then to the back of the plane.
The Chinese were talking about stand-up “seats” a year ago so they could more than double the passenger capacity. Just think. Two of these things collide and 2400 passengers die.