I have three PD-style flashlights using C-Paks. One thing that's always bugged me about the C-Paks was the way one of the edges met the clip exactly in the middle of a small hole drilled in the end of the clip, creating two very sharp pressure-points and posing an existential threat to the front-right pocket on every pair of pants I own.
I'd been contemplating a solution for years, but I always came up with something else to occupy my time instead. Today I finally did something about it:
It only took about 5 minutes per light, not counting washing and drying the parts after modification. Now my pants pockets are safe from being torn by McGizmo bear-trap clips.