Out of curiosity, is it currently possible to use a clean plate/difference matte?
In my case, I have an array of cameras that are fixed in position, angle and focal distance. It would be very useful for automatic masking to be able to provide a set of images that have just the stage and background, and then a second set with the actual subject.
Obviously, I could create an alpha mask by difference key in a compositing application, but it would be very useful to have this built into the software as it would remove additional steps.