I have not encountered many con-scripts encoding information in knots, rather than by marking flat media. I imagine that many conlangers would enjoy the inspiration of Andean khipus, which, going back to about 3,000 BCE, are ancient comparable with Proto-cuneiform.
Some useful resources include:
Various macrame websites and the concept 'sinnet' (you could decorate "nodes" within)
I think khipus and knot-writing most fascinating and I have greatly enjoyed the exercise. If people comment with specific curiosities, I will try to help. This question doesn't, per se, require an "answer" but I hope posting it may be useful and fruitful for the community.
Thanks, jk - Reinstate Monica, Andrew Ray, and curiousdannii for your input about correct posting!
One knot-like writing system (not mine) is Sylvia Sotomayor's Kelen Ceremonial Interlace Alphabet (can be found at http://www.terjemar.net/kelen/lajathin.php). It is ceremonial because it would likely be immensely impractical in every-day usage. The alphabet uses an interlace pattern where each letter is defined by a binary left-right pattern. From the author: "If these make your eyes water, don't feel alone. The idea was to create an alphabet for identifying things and places that could only be read by the initiated."
The following PDF distributed as a handout by the author at the LCC2 conference for even more information. http://conlang.org/cms/wp-content/uploads/Sylvia_Sotomayor.pdf