Kevin,
Can I visit your universe in which Unique is cleaner than a ball powder?
I never found Unique to be particularly clean burning, especially not more so than WW 231, which is my go-to powder for just about all of my handgun loading.
But Unique is cleaner than Red Dot...
"How in the world would a revolver know what kind of powder you used?"
Obviously, the revolver, being a nonsentient lump of steel wouldn't know, but every type of powder has a distinct set of characteristics that are unique to that powder, and to a degree, that type.
For example, double-base powders, because of the nitroglycerine content, generally burn a lot hotter than single base powders.
A lot can depend on how quickly the pressure rises, and how long that rise lasts.
Some of the worst powders for frame cutting are those with a quick pressure rise but a fairly long pressure pulse.