Combing raster mask with drawn and/or parametric masks

Is your feature request related to a problem? Please describe.

I frequently take pictures of wildlife. During the photo editing I usually use a mask to isolate the subject wildlife. I additionally add masks to give the photo depth etc. Under the present build as I understand it, I have to redefine the subject every time I add more masks to improve the photo.

Describe the solution you'd like

I would like to have the ability to define the subject once and have it saved as a raster mask. Then I would like to add that raster mask and combine it with additional masks to improve the photo. For example, combine it with a gradient mask to provide depth, or combine it with a parametric mask to select a portion of the subject for further editing.

Alternatives

An additional approach would be an ability to have a one click approach to select the subject.

Additional context

No files or tests are named. Start by locating the existing raster, drawn, gradient, and parametric mask handling, then determine how masks are currently combined. Done means a saved raster subject mask can be reused and combined with additional masks for depth or partial-subject editing.