I like the strain relief designed by BoSnap, it is really rigid and will not, like other strain reliefs, twist when you tourn the leveling wheels.
But on my Tornado the cables are placed left of the headbed screw. So I remixed it and I
- added a ripple on the cable hole, to prevent the cable to slip out,
- and made the part above the spring thinner, to give the spring a little more room.
It's better to use PETG or ABS, because of the heat.