When auto tagging a large collection, the process takes a long time and then sometimes, for whatever reason, the system crashes. To help starting off where the crash happened with auto tagging, it would be helpful to have a tag set on each photo after the auto scan processes the photo. That way the photos already processed (which may or may not have new tags set) can be not scanned again. At the moment, I can create a tagging-todo list by searching for last modified files, but I cannot search to find ones processed but not modified.