I suggest preserving the phenotype because I dont want to play the role of picky social engineer. At most I think certain traits like IQ and whatever contributes toward stable family formation should be encouraged to be passed on more than they are to guard against deleterious genetic drift, not with an intent to change into a vision of a better man. I am vetoing some arbitrary facts, not promoting my prescriptive vision
 
While wanting to jury rig and ideal white man, or some discrete set of values which will totally satisfy this complex machine we call society is more idealistic in my opinion than the conservative approach: we fix the phenotype rather than dither or risk our opportunity on some ideal which is only theoretical while ethnostates have existed