Depth of Field filter for viewlayers

We need camera depth of field filter for viewlayers, as we have for motionblur and denoising. in lot of cases some viewlayers need to be rendered without dof, as it has to be added and controlled in compositing. For this we now have to make separate scene and add separate camera with dof off. In heavy scene this workflow has big performance impact. Having viewlayer filter would fix this issue.