Why not load three libraries into one instance of Kontakt in the F11 rack, set correct midi tracks to receive from and send then to different library outs from kontakt via its mix panel?
Main-Intel i7/Asus mobo/Gforce GPU/16gig ram. Secondary-Intel Q9950/Asus mobo/Radeon GPU/8gig ram. Win 764bit, Cubase 6.5 & 7.5, Studio One 2 Pro, ACID, Ableton Live, Sonic Core Scope DSP Audio System, Roland VMC 7200-48 Channel Digital Mixing System & Focal Monitors. Software includes NI Komplete 8, East West Play Libraries, Heavyocity Libraries, Sample Logic Libraries Best Service Libraries, Sonokinetic Libraries, 8Dio Libraries,Project Sam Libaries, Sound Iron Libraries,Melodyne Pro, Uberschall Elastic & Liquid Libraries.