Create the outro in a separate sequence, then SAVE it - perhaps as "Outro." Don't export it.
When a project is saved, all sequences are saved. So you may want to create your outro as a completely separate project.
When your main project is complete and the saved outro is to be added, click the Menu item (upper-left), then FILE | IMPORT CLIPS FROM ANOTHER PROJECT and chose the outro's VPJ file. It will appear as the next higher sequence, normally sequence 2.
Use <ctrl-A> to select that entire sequence, then click <ctrl-C> to copy it.
Switch to sequence 1, place the cursor at the end of your project and press <ctrl-V> to paste.
Now you have the outro at the end of the project, with its independent original tracks.