I'm curious though, where did you find out all of this information about Mono-filament weapons?
Long, long ago, in the early years of the Second Age...or the mid-70's, as the case may be, I read a book called Cestus Dei. A sci-fi book about a universe where the Catholic Church takes over and is the Empire. The main character is a Jesuit priest who goes around and generally kicks butt. If I'm remembering the book right he had two weapons that totally captured my imagination, the first was his walking staff that was essentially his 'MacGyver' tool. It could do everything, but what has always stayed with me was when he was shot at by a laser, the beam would bend up and strike the top of the staff which would recharge the staff. The other, of course this is a book I read as a young boy some forty years ago so my memory could be crossed, was the mono-wire whip.
Not a true mono-filiment weapon, maybe it was three or four molecules wide, as the character could swing the whip and it would wrap about denser materials, or even people, like a weighted rope around a pole. But he could then magnetize the wire, sending the ball tip straight out and away from the base, making almost like a long foil, which would slice into many pieces whatever the wire was wrapped around. Pretty fancy.
Another book I read, more recently, was 'The City Who Fought', from the series of 'The Ship Who Sang'. In it, a young child uses mono-wire, almost invisible, to booby trap a hallway from invading pirates. Too light to use as a weapon, the kid makes a sort of trip-wire in a corridor but has too much so she unwinds the rest and makes almost a web of the wire, then stands on the far side of her trap and taunts the pirates to chase her down the corridor...'nuff said.
For BoaLA I wanted Jyn to have an ace up her sleeve that would be unconventional and nigh overpowering - after all she's supposed to be so dang good that mano y mano fights with Stompers (knight-class weapons, what's the Eldar equivalent?) is blase. Of course, stat wise a squat berserker, even using the old Super Hero stat lines isn't really all that powerful, so what weapons could she have that would push her profile past that old standard? It'd have to be a dirty trick. So, keyed explosives dummy-ed to look like grenades, non-regulation handguns, and a dirty trick to outfit your super-hero.
Take the unweighted nature of mono-filiment and throw in "I'm a miner/scientist/inventor" and a dash of the Eldar Harlequin's Kiss and Voila! One kick-butt weapon. But it has to have a weakness...several weaknesses. BAD weaknesses to explain why every Tom, Dick, and Henry doesn't sport one, after all, so you might lose a foot. Big deal! Hence the long description, the Inquisition, and possible execution.
I hope that makes sense.