It would be nice if the Palette component had buttons to move all of the items from one side of the selectable options to the other.
Many desktop applications with this style of data manipulation have these buttons to greatly speed up the process of adding large numbers of items to the selected items
[ item ] ( add all ) [item]
[ item ] ( add selected) [item]
[ item ] ( remove selected ) [item]
[ item ] ( remove all ) [item]