The seat needs enough oomph to get the heaviest pilot in the 95th percentile range out of the airplane in the worst-case scenario (which I believe is that in which the lift fan takes a poo and the jet starts falling out of the sky while flipping ass-over-teakettle).
This means a lot of acceleration for the lightest pilot, which in combination with a heavy helmet creates an unsafe condition, as was reported six years ago...
https://ericpalmer.wordpress.com/200...r-heavy-women/
Problem does not appear to have been fixed.