From what I can tell, life and safety design factor is 10. The load created by a fall is related to rope elongation, and most of the guys here use static rope. (There's a video out there showing 20,000 lb static rope failing a 5000 lb dynamic drop test, using a 200 lbm dummy.) Also, life and safety design is meant for when something goes wrong, not when everything goes right and you only fall 18". This all leads me to believe that 5.5mm is not the right size static rope for me to be hanging from.
16 inch drop creating a 32x dynamic force on a spring scale. Not sure what the spring constant of accessory cord is.
I agree that kinetic energy from mometum creates monster loads and dynometers don't lie!
It's up to the end user to have enough protection built in the system for them to have confidence.