I am certainly not an expert string maker, but after purchasing Chad's 'Doing the Twist' video and some practice it got easy, thanks Chad.
Getting the correct length with skinny strings is difficult, and as Chad has mentioned less adjustment without a lot of twists. Of course with flemish you can undue one end and adjust length as needed.
I pad with the same material the string is, using astroflight right now, 8 strand padded to 12, double served with 62xs .017 under and .021 over and it has been rock solid. D97 skinny strings elongated more than the astroflight or ultracam.
Chad, regarding squeeze out I remember reading a post a while back about using dacron for padding fast flight type endless loop strings where the dacron would move around and bunch up. Do not remember any other details though but it impressed me enough to move away from it. Do not know if it applies to flemish. One would think the way the strings are twisited together in the flemish it would be hard for the dacron to move around vs the endless loop where they are layed in and served. Heck, don't shrew bows come with the entire string padded with dacron.