Overture cardboard spool protector

I needed a cardboard spool adapter to use the overture spools to support feeding directly from the Sunlu S2. My issue is that I own a bambulab A1 Mini and cannot print the larger protectors, so I made a coil. PETG handles the slight bending and it aids it in gripping the spool. However, this is my first design after owning a printer for 2 weeks and I have not quite figured out a better retention method. I sort of imagine a staple in the holes. I'm sure someone can remix this a bit better with a better connector. Oh, and the bonus, only a few grams of filament. I would recommend PETG only, and I am unsure of spool variation in size.