Mastering: Ability to include a 'shadow' reference track?

I really like the S1 mastering application, and there's more I need to understand for sure. However, it did strike me that it is only possible to have a single audio track at any time along the timeframe. As a result it doesn't seem possible to have a parallel reference track (bypassing anything in the fx racks), so I have to do this with a separate player.

It would be a useful add to allow the user to add at least one 'reference' track, with the ability to mute as necessary within the same timeframe. That ref track would not be rendered to the final output and would bypass individual, as well as master fx inserts.