The hard modern "pleather" seats can very uncomfortable the 80s Hondas had soft and comfortable seats a light fabric design, I want to suggest a mesh seat which would be light weight like a patio deck chair and could go almost horizontal. This material can provide dampening of road vibration also.
The Aptera Forum
Interesting.
I hope someone from Aptera can speak to what they plan.
Whatever is planned it will have meet or exceed safety crash and seat belt requirements. I read....Aptera plans to have this vehicle, although registered as a motorcycle, meet or exceed crash testing of a car.
The vehicle‘s interior rendering does seem to illustrate a low profile seat. With my wife’s thin backend.... I think I would buy her a cool gel seat pad😉
I wonder what obligations a trike has to meet vehicle safety standards. Car chairs are necessarily complex and expensive. I wonder if a fixed seat integrated into the trike chassis with a movable steering column and pedal box would suffice. Downside is someone with short arms trying to reach the other dash controls.