--ask now presents a simple yes/no alternative. It could be enhanced to provide options for all packages that would be merged, using a simple interface with perhaps a tick box on every package's line, or a command line where the desired packages can be listed using a numbered list. Since the dependency tree is already established at that point, it can be used to decide which (reverse) dependencies should or should not be upgraded when a specific package is interactively set to not be merged.
