Shadows Render Over Linework in Artistic Mode

Using a custom “Artistic” display mode in the latest WIP. Shadows appear to render over lines in a way that is undesirable, see screenshots:

Shadows off: lines are crisp and dark: 58%20PM

Shadows on: light-colored shadow overlays on linework

Is there a way to control this already? May be just missing it… Intended behavior? Otherwise it seems like in most use cases it would be better to have the shadows render underneath