MultiComboBoxItem and optional datasource

I have notice that MultiComboBoxItem has slightly different behavior with optional datasource in comparision with ComboBoxItem.

ComboBoxItem does not fetch data of optional datasource on set value,
but MultiComboBoxItem does.

When method setValues for MultiComboBoxItem is invoked - optional datasource loads data from server.

Is it possible to disable this feature of MultiComboBoxItem and to allow to load data just on user interaction with component?