i'm not familiar with Magenta and Rob Reed so could be you're right.Hi Otto, no problem. I know it is not really a competition, but Andy Jackson has 4 surround mixes on his name, On an Island, The Division Bell, The Endless River and Signal to Noise.
Rob Reed has his solo album, the Kompendium album and 4 Magenta albums released in surround. Both not much but it looks like they are to stay in the surround camp.
as for AJ, he has lone album mixed in 4.0
rest three he was only mixing engineer and that's doesn't count, because
as an engineer he doing only what he was hired to do.
that being said, this left us so far with not much. only 3 from new generation artists,
who discovered, understand and employs advantages of surround mixes.