The problem with templates is you can't apply them after the fact to a project where the tracks have already been recorded. I think the best option is:
1. Open the project with the desired mixer settings.
2. Delete all the audio and "Save As" a template or project.
3. Open the new project you want to mix, and render
each track from 00:00 to the end as a WAV file.
4. Close the project, open the template, and drag the WAV files into the template to the appropriate tracks.