Don't allow image conversion to CMYK, give an option to 'bake' in a display soft proof profile.
Operating System: All
Description of the feature
GIMP doesn't do CMYK editing yet, a UI setup should let the user know. Don't allow the user to convert, gray out the button with a message?
There could be an extra option; 'baking' in the soft proof. That would be useful to me at least.