Normally Display Styles are assigned to Views. This suggestion would allow a Display Style to be assigned to a 2D closed Element or a 3D Solid Shape.

A 2D or 3D Shape Element that can have a Display Style filter applied to it.

This new Element feature would allow a Display Style to be assigned to it so that when the Shape Element is placed between the View and the Element, a Display Style is applied and the Elements behind the Shape are rendered according to the Shape size. Anything outside of the shape viewing are is not rendered.

So I can create a small rectangle and move it around my drawing or model to get a quick render of what it looks like before final production.

In a 3D model I can do the same. Using a 2D shape I can 'lens' my model and check the rendering aspects of it as i am working.

Another usage is to 'x-ray' my model in part, instead of rendering the whole model. i know i can render one View but I can see use cases where i would place a render shape over part of a model or drawing to partially render it for a drawing.