New Release on Marketplace: Sci-Fi Hallway

QQ:

Per Pixel Mask computation vs Material Elements

The Sci-Fi hallway uses a few master materials of varying styles most of which use RGB Masks, which require an entire new Texture with RGB Channels free,
Is it not cheaper to use separate material elements on objects and craft instances that are defined as material types ( Copper, Steel, Rubber, Plastic ) and use those in each element

At what point does the cost switch sides?

e.g. 10 elements costs the same as a 2k mask or something