I know it runs direct x, Ive been using waves plugs for years in CEP. I got the VST wrapper a while ago and have used VST effects (wunderverb is pretty cool sometimes) but I havent been able to record standalone synths with CEP.
You can use the B4 wrapped, but only to make other wavs sound like an organ. I have used the overdrive and leslie effects on my guitar. As far as using VST instrument...no dice.