I did not know this, so maybe I am not alone. Stumbled on it in my system when I was uninstalling/reinstalling Waves Mercury.
If I have Waves Studio Rack installed, then it is the only way to use Waves plugins with VEP6.
However, if I do not have Waves Studio Rack installed, I can use every Waves plugin by itself in any VEP channel FX slot.
This is great!