I used PLA the first time I printed this out, and it didn't work too well. The slight flexibility in the PETG works much, much better.
I got the idea for the changes required from https://www.thingiverse.com/thing:2849069
I imported all the mesh pieces into Fusion, traced the clip adapter, added some target posts, and lofted the arms from the clip to the adapter. It was my first real project in Fusion 360, and while frustrating at times, it worked well.