Can't re-import landscape

Not stoked with the way the landscape tool works.

I’ve imported a 2048x2048 landscape and I can’t reimport changes because upon import it became 2160x2160. I tried remaking it and it will not let me make it 2048. How do you get around this? Recreating the entire level just for small changes is going to make me want to quit this project.

Second, the reason it’s 2160 is it’s added **** to the edges of the map. Unwanted ****. Why does it do that?! Eg the bottom of this crop from the exported heightmap:

I ended up fixing it by resizing my world machine output to 2160 and all of my textures, which also got rid of the ■■■■ at the edges, but it was an irritating process.