Upon further consideration, if I were doing a MG-Trek hack, I’d focus more on playing in Roddenberry’s Trek universe and not necessarily restrict the Nature mechanics to the Star Fleet Academy structure.
Thus, because Roddenberry’s Trek is fundamentally racist (or perhaps, more kindly, race-focused), I’d do it this way (totally off the top of my head)…
Used for: Being bold or impulsive, dealing with new alien types, fighting
At 0: No longer interested in space travel, return to Earth
At 8: Disappear into space forever, forsaking Federation space for the great unknown
Used for: Being logical, intelligence and knowledge, controlling one’s emotions
At 0: Give up on Vulcan life, go to Romulus and join your emotional brethren (start Nature: Romulan at 3)
At 8: Return to Vulcan (or Star Fleet if in the Abrams alternaTrek) to contemplate science and logic
Used for: Being impulsive or angry, scheming, fighting
At 0: Give up on Romulan life, go to Vulcan and join your logical brethren (start Nature: Vulcan at 3)
At 8: Burn out in flare of rage, perhaps returning to Romulus but most likely suiciding into a Federation warship
Used for: Matters of pride or honor, fighting, feats of strength
At 0: Debase yourself before Klingon High Command for cowardice, accept their final ruling (OR travel to Federation Space and live as a Human)
At 8: Honor-bound and unable to operate among weaker aliens, return to the Klingon Empire … never to leave again.
Used for: Logic and intelligence over emotion, learning and training, feats of physical improbability
At 0: Become a real boy, gain full scope of emotions and live as a human
At 8: Lose any chance at gaining an emotional life, and submit to being a tool for someone’s use.
Used for: Scheming, sneaking, haggling
At 0: Give up the scheming, sneaking, haggling life and live in Federation Space as a fair-dealing merchant
At 8: Not trusted by even your own people, you create one enemy too many and are found knifed in a service shaft somewhere
Used for: Assimilating, logic and intelligence over emotion, fighting
At 0: Overcome assimilation and return to your original race (restart your “original” race at 3)
At 8: Final assimilation complete, join with the borg cube as an undifferentiated cog in the machine
If you’re half-something, pick ONE of your race’s “Used for” lists. Then, pick ONE of your race’s “At 0” result and your OTHER race’s “At 8” result, representing both ends of this particular combination’s arc. So, like Spock would choose the Vulcan “used for” list, the Human “At 0” and the Vulcan “At 8”. I might even call Geordie a “Human/Android” hybrid, taking the human “used for”, human “At 0” and android “at 8”.
Anyway, something else to chew on.