Generative FILL is awesome. I would love to see Generative ADD.
Where you can highlight an area, and content aware detail could be added to an already existing image/layer.
I.E. - I highlight the tire of an off-road vehicle and prompt to "cover the tire in light-colored mud"
It would be the perfect compliment to generative fill and an excellent standalone feature to add detail/effects to photos by creating another editable/adjustable layer of effect/detail/alteration to an already existing image or generated image.