specify different camera per viewlayer or add the ability to specify a camera in the render layer node

I'd like to render a scene from a different scene within the same blend file that is only used for compositing, allowing me to set up different compositions for different cameras.

In the compositing scene, I set the render layer node's scene and viewlayer so that it renders the main scene. I can't specify which camera to use in the 3d scene from the render layer node in the compositing scene, so I have to go back to the 3d scene and manually change the camera first.

It would be good if each viewlayer's override section let you specify a camera to use for that viewlayer.

Alternatively add the option the render layer node to specify the camera to use, rather than the currently active scene camera.