tecpilot,
Keep your hair on! The last time I did any longlining was about 12 years ago, Dyneema probably wasn't invented, it certainly wasn't when I started 25 years ago anyway!
As the AS350 is the prevalent type in Europe as the Llama fades away, I understand your need for a slightly damped cable. Yes I remember changing Starflex's in the early 80's for this very reason. We used a damper (snubber made from car tyre, hey it worked) but stuck with the steel and chain because there was nothing else.
Imagine cracking a whip and your helicopter is at the end!! Yes I do understand the dynamics, and now with a B3 operating at higher weights and loadings using basically the same Starflex it is an even bigger issue.
Dyneema or steel in the M/R probably makes no difference to the result!!
I have seen a case of a piece of Vectra that certainly had the same net result.
Remember that in most countries what you use from the hook down is NOT certified to aviation requirements. It MAY need to be certified by other authorities depending on where you operate.
Yes I used to have certificates for both cable and chain. They may be heavier, but I know which is easier to inspect for wear and damage!
My post was not conclusive as I did mention I think!
"To be old and wise, first you have to be young and stupid"