This may be a question for the developers.
I am using several Render Layers to separate different freestyle line styles. There is a freestyle option to cache the View Map, which works great if you use several line style within one line set (or several line sets within one layer).
However when is use different layers, the same scene mesh is loaded for every layer that uses freestyle. This seems very unlogical to me. I can see no situation you would want recalc the View map for a different layer.
Is there a way to circumvent this? Or would it be possible to adapt or change this in python?