random z-coordinate in axial plane of surfaces in source recon report

[matsvanes]

The coordinates that are used in the surfaces plot of the source recon report are quite random. At least the sagittal and coronal planes seem to display a frame that is more or less centered in the brain, but the axial plane is often showing a slice with a z-coordinate below the brain itself. See example here. Would be good if we can define a sensible best guess.