'undo' brush would be a great addition

It would be very helpful to have an ‘undo’ brush one might size, soften, set opacity and apply to a processed photo to selectively remove parts of the enhancement. I have found on a number of occasions that I need to reduce the amount of enhancement at the edges of a face as something looks unnatural. This has meant resorting to Photoshop for a pretty easy reversion to the original image in selected areas.

This is a great idea! Thanks for sharing.