Yes you are missing the point entirely... You have completely changed the functionality of your MultiSelect combo box and broken a cascading workflow functionality that we relied upon for a product that we shipped.
2014 release - this is what i need cascading multiselect which retains it's previous selection, I've been using this in product for over a year
http://dojo.telerik.com/oyeZU
2015 release - I consider this functionality very broken
http://dojo.telerik.com/AnUSu