The Primitive section of the addon has two check boxes: Extrude and fill.
Out of these, the "fill" check box is justified (there is a difference between ticked and clear).
But what does the "Extrude" check box achieve?

If the Extrude check box is clear, then pressing E extrudes the primitive, and creates a frame. But when we press CTRL+LMB click, it does not generate a shape. Without a shape, what are we expected to do?

In fact, the Apply shortcut (CTRL+LMB click) does not work. Thus we cannot complete the making of the extruded part itself.

In other words, we have the existing geometry, and a frame (a 3D extrusion of the primitive), which cannot be applied. We can grab and move this frame. But beyond that, the addon does not let us use this frame in creating new geometry.

Thus, the "no extrude, no fill" combination is not viable, and should not be allowed.
Or please let the user use the empty extruded frame for subsequent operations (I am not clear how).