Thank you, Hellfire for the information. But I would be looking more for the 6E and 6S type gene modifications.
Change hair, eye color, voice box, facial features, body type, type of changes. Nothing exotic.
The Star League gave people Promised Landers are rarely recognizable even with advanced medical scanners. The strong heart and high blood pressure do not exceed human extremes, nor do the toughened ligaments and tendons. They have fewer circulatory, joint, and back problems than the human norm and are tolerant of Promised Land allergens and infections. Promised Landers tend to be short, averaging 1.6 meters and are athletic like gymnasts or equestrian jockeys.
The Belters can change features, but it is expensive but everything but extra-long life in inheritable. They also change the ability to survive in space for a short period of time. Infantry and pilot modifications beside extreme cosmetics.
By splicing in another humans features it would change your DNA.