the display of the drop-down part of the multicolumncombobox is different from the RAD combo box. There is an extra line between the content of the combo box and the drop-down button in the office 2016 theme at least. This should not be there to be consistent with the other combo boxes.
when selecting more items and dropdown positioning is down and input filed has fixed width, the dropdown covers the input field.
It should move down to the bottom edge of input field.
Add non-editable feature to MultiColumnComboBox ( like on ComboBox ).