Yes, this is what I ended up doing and it works for me. I was just thinking it would be cool to use the plugin form, which seems a little cleaner. I guess I could copy the DynamicPropsPlugin and change it to work with a function that returns a string instead of a number, right?
Also, is this a good way to get the percentage complete for the tween? Or is there a better way?
var percent:Number = (TweenMax.getTweensOf(_relationshipPath)[0] as TweenMax).currentProgress;
Thanks!