It's certainly possible that I may be missing something, however while playing around making various maps I've often thought it would be nice to go back into the DM to add various erosion or other settings to land that I've altered or created. How to do this? There is an option in Operations -> Design Map -> Generate from HM, but this is greyed out.
Being able to 'work backwards' as it were, while not exactly a solid workflow, would be of great benefit. As I often find that even carefully planned landscapes will get altered during the tweaking process.
Nag.