Firstly, i love this app you've made so incredibly useful. However I was thinking of this same thing. I've been trying to get a small city with 6-8 locations marked and its a little frustrating to have to click "small" a hundred times for anything close to show up. It would be great if I could just Extend the Legend and drop them myself. Editing the numbers as is necessary.
Thanks for reading the comments as always!
If you have a specific picture in mind about required districts number, their location, shape, size etc, it would probably be easier just to hide annotations and label districts manually in a graphics editor. "District editor" will be implemented eventually, but I doubt it will happen anytime soon. It will require some significant amount of work on UI.
