New type of brush

Hi.

I would like to have a new type of brush that I believe can be made through a combination of existing brushes/selection mechanisms.

The purpose of the new tool is to make it easier to select small/intricate patterns such as leaves/branches against a bright sky.

In my imagination, it should work like a regular brush, but with additional control via a something like luma mask.

I hope the workflow proposed below explains my idea.

After selecting the tool, a control window resembling a luminance mask control appears (with similar controls). The difference is that while adjusting parameters nwe see edited image with overlays in a two colors: eg. orange for some areas and green for others, with some transitional regions (with an intermediate color). The border between regions may have blurred edges, depending on the panel settings.
Orange areas indicates selected regions and green indicates deselected regions. Their shape and area depend on the settings in the control window.
Then we can start painting actual mask - at this point we may see the red mask (if it was created earlier  eg. by AI, user's brush strokes or whatever activity) or we can't see it at all - depending on the settings in the control window. But when we use brush or eraser, a tool affects actual mask only at the regions that were marked (while parameters were adjusted) with the orange mask, leaving the "green" areas untouched, with some intermediate effects on the border regions.
The parameters in the control window can be changed at any time (when the tool is active) and these settings do not affect an already created mask (which is different from a luma mask which "adds" its settings an already existing mask). This allows you to adjust the tool settings to the actual, local image parameters.

Does it look reasonably?

Regards.

M.