Mainstage 3 and forcing instruments to cpu cores?

Question for the power users. Is it possible to force an instrument to use one core, and another to use a separate one? I remember there was some sort of bussing trick that would do this (although never really succeeded in trying it). In the Hillsong Omnisphere Sounds Facebook group- we have this constant question coming up and in my testing I have not been able to force an instance of Omnisphere to use a full core. I was hoping that there was a way to have 2 instances (or 4 for four core cpus) of Omnisphere loaded with patches in Live Multi mode- aliased to various sets. Versus having like 5 or 7 sets with multiple instances of Omnisphere loaded. Hopefully this makes sense.