Keep destination controllers determines what happens when you paste notes into a region of time where controller events currently exist, and the notes you are pasting have controller events along with them. The easiest way to understand this is through an example. Let’s say that you have copied a section of notes into the clipboard. FreeStyle has automatically included some volume controllers because they affect the notes you just copied. Now you go to paste the notes somewhere else, but there happens to be volume controllers at the location where you are pasting. When Keep Destination Controllers is unchecked, the volume controllers in the clipboard are pasted with the notes, and they replace the controllers at the paste destination. When Keep Destination Controllers is checked, the volume controllers in the clipboard are not pasted with the notes, and the controllers at the paste destination remain unaffected.
