How to control a spring ?

I’m looking to add breast physics to my character, and I’m looking to have a way to change the bounciness in play mode. basically so the movement is realistic to the shirt she is currently wearing.
(have changeable armor in the game)

I had tried using a physics asset but it would flatten the best as I made it more bouncy. I tried setting up spring controllers in my AnimGraph, it seems to work better but I have no access to dampening and stiffness to adjust any setting in runtime.

how might I change my approach ?

Is there an asset in the market place that might help?

on a side note; I wander how Square was able to set up Tiffa’s breast physics in FF7 rebirth , it seemed to have good results while not being over exonerated

You can use a spring controller

is there something I missed ?

guess i will come back to this latter
@ epic;
you guys should give a way to control the spring controller on runtime