Patio umbrella pole insert

My first make was for a coworker who asked if I could make him some new inserts for the poles of a patio umbrella. I've never seen the umbrella, but I understand that this part fits into a pocket in the fabric of the umbrella to keep it in place. There were two different sizes, but only the small one is included here. I was told that my prototype of the large piece that I made before I learned how to use hull to round the edges was good enough. This was my first time using OpenSCAD (or any CAD s