Zulu 10: You also seem to be suggesting that every design should be right first time. You’re a creationist I assume?
In the case of ejection seats with 60 years of development I will firmly put my hand up and say YES.
In my mind every ejection seat that makes it into production aircraft MUST be right first time. Creationist? maybe. I'm also someone who worked on and around ejection seats for many years.