Two variants visible on screen: one the "master variant" second the "variant in proofing mode"

When proofing an image for print I now have to go to photoshop to have two variants of the same image on screen, one in proofing mode to adapt it for printing, while the other variant is the original "developed" image not in proofing mode for comparison.
It would be nice to be able to do the same in CO, but as it is now when two image variants are opened in the viewer and proofing is enabled, both image variants are "in proofing mode". That is not very useful. I would like to enable one variant in proofing mode and keep the other variant on the same screen "as is = not in proofing mode" i.e. enable proofing mode per (image)window and not "per screen".