a couple of comments deleted following another poster's registering concern about them ... related to the earlier deletions
Now, back to an interesting question.
The magnetic pole, being a moveable feast, was something that was a gift to early navigators. Early being up until...about now. Of course we need to be independent of any single electronic system. We were going that way with INS, but the computer power was not really up to the mark then.
Now, we have the ability to measure light in a closed system, down to molecular levels, and we can certainly sum the output of such systems. The relativistic algorithms woven into the sat-nav signals, are proof of our mastery of this science. We know where we are in our orbit round our sun, almost down to the last perturbational tremor.
With what we have now, we are ready to navigate by such enclosed internal and quite independent systems...it really is time that we weaned ourselves away from electronically fragile orbiting clocks, let alone the wandering boiling mass in the centre of our planet.