Materials that inherit all of their properties/maps from another material unless overridden. We do this in Unreal all the time and it's super useful. Maybe have a "material input" spot on a material. Also when copying a material, in addition to the "instance" option we could have a "reference" option.
![teratron_0-1640932119132.png teratron_0-1640932119132.png](https://forums.autodesk.com/t5/image/serverpage/image-id/1006299i7EE88D7C23A27B16/image-size/medium?v=v2&px=400)