Photoshop tapered tool idea

I do a lot of cutout work in the Select & Mask module. I love how precise it is compared to older PS interfaces. Especially when cutting out images that have lots of "hair" or other fine details.
My request is this. Similar to holding shif while using the brush tool to make a straight line; I'd love to be able to make straight line tapers by clicking with a large brush then making my brush smaller and shift clicking with the smaller brush and having the resulting stroke taper from the larger size to the smaller size.

Cheers!