Spreading a scatter plot is accomplished by changing the values in the cells for the X axis so that the data points are spread out along the X axis. You normally do not see the effect, because the number formatting in those cells is adjusted to not show any decimals. But if you select a cell and look in the formula bar, you will see that it is actually not a whole number.
This is a companion discussion topic for the original entry at https://www.xltoolbox.net/spreadscatter.html