Excellent tool Nortantis team!
I have to say, the ability to paint visually pleasing mountain ranges in strokes rather than placing stamps individually is such a timesaver.
My feature proposal would be to import a map from an image and load it in the editor.
Basic implementation: read a black & white 16:9 image, treat black as landmasses and white/transparent as ocean/water, paint the polygons accordingly, and throw it into the editor. Being able to start with bare landmasses with predetermined shapes would save even more time.
Enhanced implementation: read a b&w image as a heightmap (such as the heightmap exported by Nortantis), paint landmasses and add the various types of hills and mountains accordingly, and open it for editing. There's some overlap in visual weight between round mountains, twisty hills, and sharp hills so maybe the type could be randomized at that height.
Exhaustive implementation: import images for heightmap and placement of each region/type, lakes, cities, or if no heightmap, swaths for the different types of hills and mountains, then paint the polygons etc. etc. Simpler to import them one at a time for each region/icon, but a unified import screen where the user could add each "layer" and select its region/icon context would be pretty cool. Only slightly more value over the basic landmass import as each layer would have to be prepared separately. Would only benefit overly fussy and fiddly mapmakers like myself.
Also, it would be cool if there were fjords for shorelines. I've got them at the northern and southern extrema on my current world map.