I'm not sure the Apple design was influenced by Prusa at all. The curved plastic is basically universal, and was present in face shields long before the coronavirus crisis. Some face shields used a rigid molded plastic shield, but that's obviously much harder to manufacture. If the shield is made of flexible plastic, something is clearly needed to tension it; the Prusa design used a rigid printed component, and Apple used another flexible component.
I'm not sure the Apple design was influenced by Prusa at all. The curved plastic is basically universal, and was present in face shields long before the coronavirus crisis. Some face shields used a rigid molded plastic shield, but that's obviously much harder to manufacture. If the shield is made of flexible plastic, something is clearly needed to tension it; the Prusa design used a rigid printed component, and Apple used another flexible component.