Map Generator is dead, quite frankly.
TTDPatch Version: r1284 and later.
Patch Feature: The Land Generator
No matter what the settings, the map generator creates land that is the entire map's height/width in either the x or y direction, but not both. In the opposite, the map creates land that is about half of the map wide, but is centred on the screen. Several landgen combinations tried, including that from when it was first introduced in the thread on the forums.