I would like to propose an ability to discard shader writes to certain color attachments if it is doable.

Use case from my codebase:
I have a G-Buffer with Colors, Positions, Normals. I want to render opaque objects first and write associated g-buffer data. These data will be later used for (SS)AO (only opaque objects get AO computed). In the second pass I want to render transparent data into another color attachment BUT ignore writes of shader to positions and normals.

In this case I could use one shader with one pipeline with the desired functionality.