can sensor level topomap tell signal's spatial information?

If sensors can measure both the magnitude and direction of magnetic field activity in the brain, then plotting the signals at sensor level as a topo map may not necessarily convey spatial information. This is because assuming that the signal from a sensor at a certain location can represent a sensory variable input does not guarantee that this location corresponds to the origin of the signal source. Therefore, what utility does plotting sensor-level topo maps serve? What information can we derive from them?