The problem is that a lot of the time ⇧⌘F is the user saying “I want to do a new folder search with my current project / selected items in the file browser” rather than “bring back the previous search I did”.
What I have been wanting to add is history to the find dialog with ⌘[ / ⌘] to go back/forward in the history.
That seems like it would be good: Just a key stroke to get back to a prior set of settings.