First I modified the hook for easier printing. It includes pillars and a wall that can easily be cut away after printing. No support is required anymore. Second, I made it less pointy and added a bevel to the top and bottom edges.

I'm using it for 3mm Bungee, and printing at 70% size works perfectly. I printed with 5 shells, 25% fill and .15mm layer height.

A great big thank you to the original designer for including the actual CAD files with his upload! It makes all kinds of remixes possible. I wish more people would do it.