This is my use-case: I am generating about 20 postcards that are simply artwork on a white backround. The scans of the artwork all have a white border, but sometimes the border is not even on all four sides. It would be great if I could see the outlines of the postcards (which are just rectangles with no strokes) AS WELL as the bitmap images on the artworks, so I can tell if the artwork is centred in the postcard. However View -> Outline just shows the outlines and View -> GPU Preview just shows the artwork as it will be printed.
I have found another method that works: Having a duplicate layer of the postcard rectangles with a black stroke instead. I make this layer visible to center the images in the postcards, then turn if off again. But ideally there would be a simpler way to do this. I am loathe to have a layer that always shows the outlines on the screen but then doesn't print them (which I could set in Layer Options), as this may confuse other people who have to work with the files.