If you load an image wiht large pixel spacing, im my case 1km = 1 000 000 mm (radar images), the crosshair disappears in coronal, sagital etc., in 3D it remains
It seems that the crosshair depth is something like 1mm and so it is not painted at larger spacings...
Maybe the line with of the crosshair should refer to the display with of the multi widget instead of the image spacing...