Simply tuning the model to generate a diverse range of people when a) the prompt already implies the inclusion of a person with a discernible race/ethnicity and b) there aren't historical or other contingencies in the prompt which make race/ethnicity not interchangeable, would not feel overbearing or degrading to performance. E.g. doctors/lawyers/whatever else might need some care to prevent the base model from reinforcing stereotypes. Shoehorning in race or ethnicity by rewording the user's prompt irrespective of context just feels, as I said, hamfisted.