To reflect on the actual topic, I have a hard time finding a usage for the crosshair too. It is a singleton, and so there is a single crosshair in the application, sort of like a “current point of interest” as I interpret it. The one thing I can think of where crosshair is more than slice intersections is that it is visible in 3D. Maybe we should add a checkbox for slice intersection visiblity in 3D and get rid of crosshairs altogether?