I’ve used the knot above to put a slight bow in the vertical carbon fiber spars of my myog backpack. They have held over several months of daily use, under tension. They still adjust easily so I can take the frame apart.
I also like this knot because it holds its position when the line is slack. You can, for example, adjust tarp lines the way you want them, pull the stakes without adjusting the knots and know that the lines will be the same length next time you use the tarp…..but still be adjustable if desired.

