oh forgot about that, but perhaps op can make his own cotton inverse string.
Cotton string breaks so quickly… I would hate to make my own cotton string for fixed axle play.
Just know that you’re not alone! Other lefties have played fixed axle before! They just threw sidewinders and UFOs. 
Although the life of a cotton string is short, you’ll probably also find that it starts to respond more after 10 or 15 minutes of play. Brand new cotton string just seems to help less with response. Could be my imagination, but that’s how it seems to me.
I’m still using the cotton string it came with. I don’t know, it’s odd. It’s really weird, going from Poly to Cotton.
You bet! Sometimes it’s a snarly tangly mess. 
Yeah, I burned my fingers up pretty good my first week of serious fixed axle play. Good old cotton.
Maybe inverse 50/50 poly cotton