This would be really nice. I could save a lot of time and drive space this way. That way I could send a matte to a comper and say “If you want just the windshield, it’s the red channel, if you want the tires, it’s the green channel, if you want the Body of the car, it’s the blue channel, and if you want it all together, it’s the alpha.”
I think we could just have a pulldown menu after the layer names in the export menu?
Of course, it would be completely sweet in the future (because most comping apps don’t yet support it fully) if we could just write all these layers out to EXR channels.