Like this but smaller in diameter and they wouldn't be as thick. The flat ones will be easier and cheaper to make. A replica of the stock cap with a flat top has a lot more curves and dimensions so it would be harder to create
I think I like the look of the stock cap a bit more honestly. The design of it reminds of the centerlock wheels on the upper tier Porsche 911s. It would be cool if you could find a way to recreate that look with the hub centric cap.