Hello Jeremy,
I've been sort of testing Metro 7 and was able to place a 16 instrument plug-in library instance such as Garritan Personal Orchestra on a track and load twelve or probably sixteen instruments into the Garritan player and create twelve MIDI tracks and render them to audio tracks and then add effects. I didn't have good luck trying this when working with Sections and then expanding them. I don't believe I could place a library such as GPO on a track and not a aux buss with Metro 6.5xx with out it creating problems.
Does this sound correct and would it then allow you to use more library instances from different libraries than previously possible as long as you work with one Section?
Phil