I think the point of being "in the library" is what distinguishes ordinary files from files that can be indexed and searched. I wouldn't want every file indexed, labeled, and searched. What I would prefer is that "in the library" didn't have to mean "copied into internal memory". If the library keeps full pathnames to files it should be able to find files on the external SD card. If a file moves then the library could prompt to try to relocate it or remove it from the library lookup.