Qidi Box Spool Holder Extender (for smaller spools)

As the name states, it is an adapter to use smaller spools in the Qidi Box while retaining the current spool roll. The second image showcases a roller sleeve to center the spools (still tweaking on that). I tried to extend it a little at the top part to reduce the need for major supports. I am in no way a professional, just tinkering/designing for fun. Do input any advice/recommendations to improve the model. Thanks!