You can now flex both linear and radial arrays to values of 1 or 0 in the Family Editor.
In the Properties Palette Other, change the parameter value as desired. Alternatively, you can change the number of elements in the array from the Modify tab
Properties panel
Family Types Dialog
Other.
Example of a parametric family array flexed to 2 in project, then 1 and 0:
See Arrays of Elements.