So, the lat long appears whatever type of planet your on. And the compass appears after you drop whatever planet your on.
Therefore neither relies on any properities, magnetic or other, of the planet.
If your going to show lat/long in orbital cruise, there is no logical reason not to show compass. After all, a simple computer would be able to compute direction just by monitoring the lat/long figures and computing a vector over a period of time.
So, please, pretty please ;-)