I got halfway through a floss mod on my Model M the other week and ended up undoing it after testing and fiddling with that half because it was far too difficult to get a uniform feeling across the board. Did you run into any similar difficulties with the F and the paracord core? I wonder if its flexibility makes it a less finicky solution. It sounds very uniform on the video. It seemed to me like the smallest changes in either the length of the floss or the seating in the key would result in anything from not seating properly to making no difference at all.