they do infact unscrew themselves nomatter how you screw them on, considering they dont have set screws on the side, rather top down. theres no way this wouldnt get shaken off easily as you have to use the lace itself itself to tighte, theres no way to insure its tight enough without destroying the laces by twisting violently.
quick solution, use threadlocker. they will still be removable without destroying the laces while twisting then off, but enough to prevent movement causing them to fly off. altho ive tested and they require significant force to dislodge with medium blue threadlocker, id only reccomend doing that when you need to remove the laces and have a new set to be certain youre not destroying your only pair.
future design? a tiny glasses sized set screw on the side, not as fancy, but far more reliable out of the box, or threadlocker and instructions about installation, like shrink tip length you have to trim to make them look right etc.