Alpha Channel in Texture Painting

I'd like the alpha channel in the color palette in Texture Painting as we have in Shader Editor.

We need to change Blend mode to erase lines on the image with its background set to alpha 0. It would be nice if we are able to switch drawing and erasing just by switching colors (black with alpha 1 for drawing and black with alpha 0 for erasing, for example).

Thank you.