The ItemTemplateSelector property doesn't work for the items in the overflow button's drop down As a workaround instead of ItemTemplateSelector you can use the ItemContainerStyleSelector property of the breadcrumb.
In MVVM scenarios if you try to set the CurrentItem to the Breadcrum's Header it won't work if there's no TextModePath. Fix is available in LIB Version 2014.3.1208.
When the items of the control are reinitialized an exception can be thrown in certain scenarios. Available in LIB version: 2014.3.1110