FL Studio 9.5 will introduce a new wrapper that can be set to run plugins 32/64 bit in their own 4 Gb/Unlimited memory space. All without touching FL Studio's memory allocation.
Running 32 bit plugins on 32 or 64 bit windows - Each plugin has access to a maximum of 4 Gb of it's own memory space.
Running 64 bit plugins on 64 bit windows - Each plugin has access to the maximum memory your PC can support.
Also das schaut ja mal sehr interessant aus! Zum Glück macht IL mal was in die Richtung...