Your (2) is exactly the kind of situation I was considering with my suggestion as well as supporting better MRC generally by removing some of the load from a multi-channel pre-pro (though I had not considered the potential processing latency issues until after I posted). We of course already have potential in EBA.
Re your (1), don't underestimate the importance of the surround channels in Trifield. The 'Tri' refers, I believe, to dimensions rather than three speakers. As you point out in your post in the Sooloos Line Update thread - there is always the 861 for that...