For me personally, it'd be much more useful to have it save the export path information inside the file itself (and if the path doesn't exist-- say, after being loaded onto another computer-- to just default to the source file's directory). Using relative paths would probably be the best way to go about it, because then it'd still apply to the case where two people are working with the file and sharing the project via source control.
Remembering the path only during the session would still be useful, but not as useful, in my case personally.