Because the metadata doesn’t seem to support variables, I think the only way to do this (sort of) efficiently in Elements is to burn a CD with CD Text and ISRC and import the CD to files transferring the cd text metadata. Then you don’t have to deal with region markers or rendering tracks one at a time or manually entering metadata for each track render. But you have to burn a cd. And it’s 44.1 khz 16 bit only. And there’s no axml ISRC in Elements at all.