You can wire the keyup event of the visible input element
and modify its value. Please note, however, that if the value of the input cannot be found in the data source then it will be considered as a custom one and widget's value and text will be set to it. In other words if "A22345" value is selected and then modified on keyup to "A2-2345" widget will think that this is a custom value and its value and text will be set to "A2-2345", which I believe will be undesired behavior.
The only feasible approach I can suggest is to modify the data items in the data source before binding the widget.
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