Reiju is the living proof that it's possible to get the superhuman abilities without losing his emotions.
Reiju is not from the same throw. she was a "failure" on Jajjis part not through intervention from Sora.
same as her siblings she manifested her super human abilities since childhood. Sanji never once did.
the genetic alterations are not dormant, they were prevented from even occuring by his mother.
the only thing Sanji showed ever since his inception were his eyebrows. his genes were modified and we now have the result.
swirly eyebrows.