Smart brush is essentially a mask, but with a smart painting. This brush is a set of: Paint(required) and any corrective layers above it. For example, when I create a mask, I create a sublayer Paint, over the fill of the bnw spots in multiplication mode, over the blur filter, etc. Now drawing with such a brush I will not have to re-create in the mask three sublayers. In contrast to conventional brushes, we have the ability to adjust all layers of the smart brush at any time. The ability to save such brushes makes them a special and important tool in the work. It will give a huge freedom to creativity.
What you are describing is feasible with the smart masks or smart materials. While your worlkflow is legit, it can be hard to integrate with the exisitng one.