Rendering Mask

My idea is to set this feature as an on button, which can show those objects with shaded rendering or not rendering under the condition of covering with white film. This will provide a better workflow for low-VRAM users, because in this mode, the rest will only be displayed as white (or specified material) to better focus on the objects rendered with mask. This will allow low-VRAM users to test render at a larger resolution.

Or is there a technology that saves the current camera perspective rendering, and automatically saves the texture baking or lighting cache for the scene when the lens is not moving, so that when the material is adjusted, only a small amount of regional changes or only the shading changes of the model are calculated, which will save a lot of memory, which will be very effective for indoor still frame rendering.