Just a thought that, when exporting an Entire Mix, that the mix exported is only as long as the last unmuted clip's ending. For (a bad) example, if you have one
muted clip that runs on for 10 minutes past all the other clips in a mix, but you export the Entire Mix, your exported stereo track will be 10 minutes longer than audio plays.
I'd love to see a checkbox in Prefs for "Export to last un-muted clip", to shorten the resulting mix to the end of the last unmuted clip.