A new exploration data type to add to explorers' earnings and reward actual exploration of a planet's surface. This would add a further layer of data underneath honk, FSS, and DSS that would sit close to the Odyssey plant bagging, and codex stuff for surface features.
These "surveys" would just involve continuous low flying or (for better reward) driving, or (better still) on foot. A special sensing array module could be made purchasable that enables/enhances the scan (and its reward).
The survey would cover a swath centred on the CMDR's path taken. Rewards would initially depend on the total swath area covered.
There could be a multiplier for exploring interesting areas (mountain ranges, giant craters, geological transition zones, biotic-rich areas). Or alternatively indicate waypoints explicitly, representing valuable areas to survey (ideally, allow reinitiation of a survey at the last waypoint after logout or ascent away from the surface).
Pilots would be able switch between ship and SRV to traverse tough terrain (but proportionately altering the reward).
You could have a "first surveyed" award for the CMDR that first completes full surveys in all of a planet's distinct geomes.
The idea is to, in a simple way, add some task orientation within exploration, and some motivation for a planetside "journey", and to mitigate its credit opportunity cost (be it as a casual explorer, or a circumnavigator, hooner, SRV racer or whatever).
Given the new planetary tech is a selling point of Odyssey (yes, yes I know), this idea directs you to actually go and indulge in exploring it as part of a role. Also, it's odd for a planet's surface to be considered fully mapped from a matter of lightseconds away, never down in the dirt - getting up close should always yield otherwise unattainable data. "Scientific" exploration data gathering should have many layers and this would add another to the existing ones.
So that pretty worlds of all types can be valuable to survey, I'm inclined to think there should be decent rewards for all planet types, or at least less predictably based on planet type (remembering that e.g. there are lots of tourists and scientists in NPC land that would, in-universe, create value for interesting or remarkable places, along with who knows what other reasons).