Changing the intensity of only a part of baked lightmass?

Hello, I was wondering if it is possible to change the intensity of the portions of lightmass? I know how to change the intensity with post process volume but can this be done to only a part off the baked map? For example if I have 2 hallways and I have baked static lights in them I would like to be able to use post process volume to turn down the intensity of only one hallway. If this is not possible is it how much more costly to use stationary lights instead of static lights? Thanks.

Anyone? Or if altering the part of lightmap is not possible is it possible to bake multiple lightmaps and have them on on one scene on top of each other?