I don’t think this is something that is really possible although, with Vienna Instruments Pro, I copied the VSTi ddl and renamed it so I could have various VEP instruments (i.e. Rhodes.dll, Wurly.dll, Piano.dll etc.)with there own quick controls. Not advised but it does work (only with VST2). I suppose you could do the same with Reaktor.
One big problem is however, whenever you update, you have to re copy and rename everything.