jayelfisher The “Delete All” button can be grayed out if there is no access to the files right now (drive is disconnected or read-only).
Third line has to button for automatic deletion since app cannot decide which of copies needs to be deleted and which needs to stay, you need to make this decision. Imagine there is photo a.jpg that is in two folders inside “old pictures” directory, “Me and my wife”, “our wedding photo shoot”. How can app decide where to delete and where to keep? It can’t, that is why there is no button.