I need the ability to change the master track in a multitrack session from Stereo to 5.1. If I start my session editing in Stereo, there is no way for me to switch to 5.1 when I am mixing on the mix stage. I have to create a brand new session. In addition, there seems to be no way to import my tracks from one multi-track session into an existing multitrack session, which makes it very difficult to work in sound editing teams.