Expand folders when dragging over them: If turned on, you can drag files over an unexpanded folder and it will pop open, letting you drop the files into one of its sub-folders.

Collapse after drag (spring-loaded): If the previous option is turned on, this option makes the folders that you've dragged over close again after the drop is complete.

Expansion delay: Configure the time (in milliseconds) that you need to hover the mouse over a folder during drag and drop before it expands.

Remember expanded folders when going back and forward: Any expanded folders will be re-expanded when moving back/forward in the history list.

Remember expanded folders when refreshing: Any expanded folders will be re-expanded after the folder is refreshed (e.g. after pressing F5). Also has the side effect of preserving the file display's selection and scroll position refreshing.