Sara I don't think I could wear a corset 24/7, but certainly it is comfortable to wear all day. It is weird that it is so hard to get a Chastity belt to fit in the same way.
I think the main reason is the stiffness of the metal. For a perfect fit, it has to be bent exactly to your individual shape everywhere. In addition, there are areas of the CB that are unfavourable in terms of construction and therefore pose a greater risk of skin irritation and pressure points.