In season 1 of “Star Trek: Strange New Worlds,” Una’s mysterious past is revealed and her Illyrian heritage is unfortunately discovered by the Federation, but in “Ad Astra Per Aspera,” we learn more about her personal history. She and her family could “pass” as human (which is a metaphor too big to get into here), and when people discovered that they were Illyrian, they were discriminated against. People in the Federation simply could not separate their ideas about genetically-enhanced individuals from their hatred of Khan and his kind. Look, just because people are in the fairly progressive Federation doesn’t mean they’re free of prejudice — even James T. Kirk had his own issues with the Klingons.
Illyrians are a semi-nomadic humanoid species that augment their physiology in order to adapt to the planets they live on; instead of colonizing planets or forcing them to bend to their will, they adjust accordingly. That’s honestly pretty commendable, but the Federation’s fears over what’s happened with augmented individuals in the past means that they’re just not willing to bend. In fact, genetically modified people are still banned from serving in Starfleet well into the future. Dr. Julian Bashir (Alexander Siddig) on “Star Trek: Deep Space Nine” also came under investigation because his parents had him augmented as a child, decades after Una’s trial.