Using Live Effects Functions for Illustrator (expandAppearance)

I have been using the excellent live-effect-functions-for-illustrator https://github.com/mark1bean/live-effect-functions-for-illustrator  

Only one small problem: I cannot get Expand Appearance to work. What I am doing wrong here:

//@include LE_Functions.js

for (var i = 0; i < app.activeDocument.activeLayer.pathItems.length; i++) {

    LE_OffsetPath(app.activeDocument.activeLayer.pathItems[i], {offset: i*5, expandAppearance: true});    
   
}

@m1b