maybe my understanding of binder.setAutoSelect might be wrong, but as it says "True to select the first model after the store's data changes" I would expect that, when set to true, the binder would also select a new item after store.add and select the parent item after store.remove. At the moment, the effect is only that first item is selected when the store is initially filled with data.
Bug or Feature? If latter, IMHO the documentation should clarify this more specific. Also, I would wish there was an easy way to have the binder select a new item afer store.add and a valid parent (or sibling if parent not existing) on store.remove. Or, have I just missed such a feature?