Maybe swings in coach would be best. They can accomodate much larger people, the snack could be held, turbalance would impact people generally similarily. Innovations could include adjustible chain length to accommodate leg length, padded seat harnesses for safety, and under the seat hooks to hang carry on baggage.

On longer flights we could have hammocks, so everyone gets a "sleeper" seat.

Time to "think out of the box"