what kind of room is that?
well, whatever. you know what you need. i'm sure a developer could do this for you if you pay them. by the way, those devices were made to generate a stereo signal from a mono input.
i'd record an orchestra in a room that sounded good. if it's just a stinkin' vst and i really needed incredible ambience, i'd probably effect the orchestra seprately from the other elements of the mix, and then, i'd use a single stereo reverb from a mono source to make a room for the entire mix, including the effected piano or "orchestra" to live in, but that's just me. as i said, i'm not against stereo auxes, i just don't usually need them. actually, when hardware was the only choice and computers could barely be trusted with channel automation, most reverbs had stereo inputs, just in case, but most mixers had mono auxes, my Soundcraft that was about $18-20,000 in the late 1980's has mono auxes. surprise! the tt patch bays' fx section are wired for stereo fx. yep, stereo reverbs have almost ALWAYS been used with mono auxes. it's really digital consoles that have made stereo auxes common in hardware today.
the incomplete phase cancellation in full streo mode really only indicates bad phase anomolies, which are what give the inpression on an extremely wide stereo feild. depending on the material and it's purpose as well as how it will be listened to, this could be good or bad. for a dance mix, it would suck, since most dancefloors are in mono. if there are phase issues, then the track will sound really crappy in the club. if it's going to be heard primarily with headphones or earbuds, then phase problems don't matter..