In shotgun loading, the size of the shot is not as important as the total weight of the shot.
For example, if you wanted to load 1 1/8 and 1 1/4 oz loads in 12 ga, Unique can handle both.
However, if you want to load 1 5/8 oz max velocity loads in 3" magnum 12 ga, you need a slower powder.
I'd say you really need 2 powders to cover the full range with any efficiency. When the slowest magnum powders are used in 1 1/8 oz loads, they are pretty smokey.