I downloaded Proteus VX sometime ago, but never installed it. I just tried it in Sonar Plat (with latest updates)....
The GUI doesn't show using Sonar's Bitbridge, but I got it to work with jBridge (v1.65). There were no presets showing up at first, but after fiddling with it, found the instrument database (You have to index it the first time you use it), then I was able to call up a piano and play!