In the export audio menu there could be an option labled “Export Parts”. It would have four check boxes and you can check multiple choices. There will also be a Truncate Parts option for shortening exported parts. There would be a checkbox for Song, Layers, Sheets, and Tracks. By default only Song is selected. The exported parts would take in account their position in the song, for example, if you have a layer that only appears in the middle of the song, the exported file will have plenty of empty space at the beginning and end of the file. The Truncate Parts option can be used to remove unused space though.
This would nice for people who use V4 for just composing and want to do the mixing and mastering with an external application or for people who want to process parts of their song and import those as a sample.