They did just that with Airto & Deodato's In Concert album (though it was never revealed what specific decoder model was used) and I remember it drawing a lot of criticism around these parts. Plus, I'd imagine that surround music fans looking for encoded material to feed their matrix decoders are an infinitely smaller subset of an already niche market.If all that can be found is a quadraphonic matrix encoded (QS or SQ) 2 channel master recording, maybe DV could consider using a Surround Master to decode it to have a quadraphonic version for release on an MCH SACD.