Once I have multiple items selected, I want to be able to remove multiple items from the selection without shift-clicking each item individually. I need a way to do this spatially rather than filtering down to one item type.
For example, I could hold Shift, click, and drag to remove items from the selection. Clicking and dragging draws a temporary selection box. When I un-click, all items (partially or completely) inside the box will be removed from the selection.