Allow me to paraphrase from the Ourchair Archives:
The Ultimate Universe is less about being 'realistic' than it is about contextualizing the outlandish, the superhuman and the fantastic within a twenty-first century setting. It does not necessarily 'fix' what has been done forty years ago, because what Stan, Jack, Steve and the rest of the crew did was never broken in the first place.
In the 60s, these effects were seen with how mutants were seen as an insidious social menace not unlike the red scare, and what the impact of a living legend would be on a society that has had 15 years to get over the patriotic unification that defined the 40s and how a masked do-gooder would be viewed with suspicion by the press.
However, in the Ultimate Universe, mutants breed more than just street-level prejudice but an insecurity that would make mankind feel the urge to develop a protectorate force against the threat of the superhuman. This time, that peacekeeping force would be subject to both celebrity worship and left-wing suspicion.
This time, scientific research is an endeavor no longer viewed with the idealist notions of 'progress for its own sake' and the humanist vision of the explorer as hero, but rather, scientific research is purpose-driven and fully realized as part of a military-industrial complex.
Thus in the modern Ultimate Universe, 'realism' is not necessarily maintained by CURTAILING the fantastic, but by merely taking the same philosophy to a new era. In fact, this is precisely what makes it so 'down to earth' --- it adopts the classic Marvel attitude of what would happen if the strange and the bizarre happened in our world and how would we react to it realistically? What the Ultimate Universe does is place create NEW context but same attitude.
So what is it about goblins, wizards, and demon shamans that crosses the imaginary line of 'realistically fantastic' and 'overly outlandish'? How do we define that line? And for that matter, how hard should it be enforced in proportion to the ends of the Ultimate Universe? Dr. Strange has great potential because it presents elements of the fantastic that are ultimately inexplicable.
Ultimate America reacts to scientific mystery and post-human scare by attempting to create measures of defense and control. Ultimate Strange presents the possibility of seeing this fictional America react to the very things it cannot comprehend, that it cannot reasonably contain.
So in my opinion, Dr. Strange should expand the Ultimate consciousness into new frontiers --- beyond the geopolitical superpowers and the urban politics of crime, beyond the endeavors of reason and invention and beyond the sociopolitic of evolution. Ultimate Dr. Strange is where the Ultimate Universe should contextualize metaphysics to our time.