If you switch yes/no on the button from D. it should keep the list in memory so you can compare what you gain by including subdirectories, and can immediately switch back to the old (no subdirectory) version, without it rescanning the directory structure.
If the selected folder is changed, theses lists in memory should be deleted, so they get rescanned.
If you switch yes/no on the button from D. it should keep the list in memory so you can compare what you gain by including subdirectories, and can immediately switch back to the old (no subdirectory) version, without it rescanning the directory structure.
If the selected folder is changed, theses lists in memory should be deleted, so they get rescanned.
This is in the 'nice to have' category.