Photoshop’s new Selection Brush helps control GenFill

Soon after Generative Fill shipped last year, people discovered that using a semi-opaque selection could help blend results into an environment (e.g. putting fish under water). The new Selection Brush in Photoshop takes functionality that’s been around for 30+ years (via Quick Select mode) and brings it more to the surface, which in turn makes it easier to control GenFill behavior: