multiple lightmap work-around

I'm developing a VR arch-viz environment in which the player can switch on and off different objects and layouts, i.e. two different kitchen layouts that include different walls and other geometry. Obviously baking the majority of the lighting data is a must for VR but how can I bake the lighting for both kitchen layouts if they overlap when both are turned on? More clearly, if I bake the scene with one layout turned on, the other won't have any lighting data, but I can't bake the scene with both layout objects turned on simultaneously because they interfere and overlap with eachother....

I've also been trying to generate lightmaps in 3ds max and apply them to legacy shaders in unity but can't seem to get that to work either. Any help would be greatly appreciated