Spurious argument, you cannot blame the RAF for ejection seat (and their parachute) design, something that has evolved over time. Many 18 year old boys were outside seat limits for being too tall, or too short, or too light.
Hmm, you definitely can, they wrote the specification around the 95% percentile European male weight and physical dimensions.
https://www.whatdotheyknow.com/reque..._passthrough=1
US paper, but the principle applies..
https://core.ac.uk/download/pdf/36735983.pdf