Slitherine

The editor has a re-sizing function and map offset functions, but when I use them on an existing map, it "blanks out" all the tile content to whatever tile is selected in the tile list. Doesn't that render this function non-functional? Or am I missing something as to how to make use of this tool.

What I'm trying to accomplish is to make a slightly smaller sub-map out of an existing scenario and shift it to one side by about 10 squares.

Thanks!