Hi Dave, I would echo what SwitchBack says. Yes, You are correct in that mastering assumes the song(s) is/are done. However, with Studio One, it does not. And while heavy plugin lifting can be performed at this level, any overall editing aside from clip gain adjustment needs to be edited back at the song level. Is what it is. It would be a nice adjustment. Only it sort of breaks the barriers of having to refer back to such an extreme kind of edit.As mentioned above, time stretching is not part of mastering. The project page assumes that your mix is done, the song is done, all that is needed now is to optimize it for radio or streaming, and enhance the sound if needed. This is the stage where you utilize more resource heavy plugins for example, which you can't use while mixing because it takes too much CPU power. So to summarize: Song page is to finish the song, project page is to enhance the final result.