For example: if I use a section plane to show the interior of a house (and if I have shadows enabled), the sun will stream into that space as if the exterior wall doesn’t exist. This impacts daylight studies. And I suspect the current behavior isn’t often useful.
I suggest having an option in the section plane, or the object casting the shadow, or perhaps a global toggle. Maybe even just change the default behavior.
I’m aware of a workaround involving transparent PNG textures. I haven’t tried it, but it seems like a hassle.