If you are referring to the white space on the right side of your map you should just need to resize the window containing the graph. Once you get it 'right' you save a script to keep track of the plot size. Here, a ratio of 490:500 makes a shape fit the plot area with no white space.
PS: The shape is exactly 2 by 2, I do not know why the window size needs to be different than 1:1.
Graph Builder(
Size( 490, 500 ),
Show Control Panel( 0 ),
Variables( Color( :X ), Shape( :Shape ID ) ),
Elements( Map Shapes( Legend( 15 ) ) ),
SendToReport(
Dispatch(
{},
"",
ScaleBox,
{Min( 0 ), Max( 2 ), Inc( 0.2 ), Minor Ticks( 0 )}
),
Dispatch(
{},
"",
ScaleBox( 2 ),
{Min( 0 ), Max( 2 ), Inc( 0.2 ), Minor Ticks( 0 )}
)
)
)
Map File