Moral realism can be useful in letting us know what kind of things should be considered moral.
For instance, if you ground morality in God, you might say: Which God? Well, if we know which one, we might know his/her/its preferences, and that inflects our morality. Also, if God partially cashes out to “the foundation of trustworthiness, through love”, then we will approach knowing and obligation themselves (as psychological realities) in a different way (less obsessive? less militant? or, perhaps, less rigorously responsible?).
Sharon Hewitt Rawlette (in The Feeling of Value) grounds her moral realism in “normative qualia”, which for her is something like “the component of pain that feels unacceptable” or its opposite in pleasure), which leads her to hedonic utilitarianism. Not to preference satisfaction or anything else, but specifically to hedonism.
I think both of the above are best grounded in a “naturalism” (a “one-ontological-world-ism” from my other comment), rather than in anything Enochian or Parfitian.