Yeah, I think I see what you mean. I’m very plastic conservative so I hope I can go without printing a second one, therefore the clip idea. Also the clip is a bit more practical better looking.

They fall out. For now I use a rubber band around the case but I don’t like that solution too much. The initial idea was to put a rubber band around the “waist” so that they would be held there. Unfortunately the rubber then doesn’t touch the dart. My current idea for a fix is to make a clip that pushes against that darts sideways through the holes.

This is fantastic! I have half assed plans of a similar design in FreeCAD lying around. I haven’t come around building it yet. I’ll surely take some inspiration here.