As a Roblox developer, it is currently impossible to disable shadows on specific parts and not others.
I could see this being useful for areas where you want to be able to see the sky, however there is stuff around you. What you would do in that case is put completely reflective parts around the box right? But the problem is they’re still affected by shadows and it ruins the immersion. If we could disable shadows on specific parts this would be a feasible thing to do.
Though it may be a rare occasion, maybe people might use reflective parts to give off the appearance of a sky and have, for example, a room or something above. I don’t know—just my thoughts.