Show render region as a bounding box with a passepartout option. Additionally, a text info is shown at the upper left corner, similar to the info text in 3d view, showing the render size and current image size. Devtalk thread: https://devtalk.blender.org/t/compositor-ui-improvements/34186?u=izo Pull Request: https://projects.blender.org/blender/blender/pulls/120471