Message Class Archiving Granularity

As it stands you can only block manual archiving for message classes which you don't automatically archive. I think it would be beneficial to have more granularity in the settings instead of an all or nothing.
For example, I don't want to automatically archive IPM.Note.Voice, IPM.Task, or IPM.Stickynote. However, I would like to allow the manual archiving of task and stickynote while still blocking voicemails altogether.