I use Subterfuge too.The problem with fluorocarbons is they're designed to be stiffer than mono and the majority of fluoros didn't use to be pure.The only ones that were pure were Gardner Subterrfuge and Korda IQ,the problem with impure fluorocarbon was that it's brittle and it's breaking strain is under the manufacturers stated b/s.
Fluoro has great anti ejection/tangle properties so if you want a flimsy hair ,you're gonna have to use a seperate one made from either hair braid or floss.Maybe use Korda Hybrid,a flurocarbon coated braid and just strip the coating off the hair for a flexible hair,the rest will remain as stiff as fluoro with almost the same invisiblity.