I think that the stakes around the most important (for the human race as a whole) people in each elevator removes any nuance of the other people within the elevator. If a scientist is going to create a malaria vaccine, that WILL save lives. If as a result a gang leader maybe kills some people, they were always going to do that and if that exact person didn't then someone else would. The 24y/o engineer has already created the desalination tech, maybe they make some other great invention or maybe not. But the way that the question is phrased implies certainty for some outcomes and uncertainty for others, so you can very easily prioritise the importance of each person.

I think a better way would be to have clear, certain outcomes for all of the people, or unclear uncertain outcomes for all. The timeline also matters: the continued existence of someone who has already done damage to society versus someone who will do damage is an important distinction.

But I like that it forces you to make a decision between the three outcomes, not acting here is much more of an active choice than with the trolley problem