I have base game and all DLC through Steam.
Currently when I load an empty map on the map editor it loads a 240 x 240 size irregardless of the size selected.
When I load a random map in the editor (not empty) it seems random whether or not it will load the correct size. I have not found a pattern of the occurrence.
This all makes me sad. Thank you for an awesome game though.
P.S. All the map editor tools that have been suggested, I want them so bad I would pay you money for them.