It would be nice to be able to add multiple regions of an image to be rendered at the same time in the Render Frame Window, all editable independently. There have been several times where I wanted to re-render a few different areas of reflections in an image and it gets tedious to have to render a region, move region and rescale it, render region, move region and rescale it, ect. This would help save time when having to knock out lots of renders as quickly as possible.