When it comes to generating unusual and (to many people) offensive opinions about morality, scepticism about the ability of anything to affect long-run happiness truly is the gift that keeps on giving.
A relatively tame example is the idea that, since most lives are good, we should therefore devote our resources as fully as possible towards increasing the world population. The moral premises here are controversial but I think defensible - ultimately, total utilitarianism across the span of actually-or-potentially-existing moral patients.
An edgier way to take this is to observe that people from oppressed and marginalised groups are likely to be used to their subjugation due to having grown up in similar (or indeed worse) circumstances, and therefore to suffer far less from it than someone who is thrown into this situation. That is to say, the experience of a white person who suffers racial discrimination is likely to be severely more negative than the experience of a member of an ethnic minority who suffers similar discrimination. Combine this with premises about the interests of all counting equally, and you end up concluding that racism against whites is significantly worse than racism against (for example) black people.
This is a surprising conclusion, and my inclination before endorsing it even tentatively would be to go over the reasoning leading to it with a very fine-toothed comb. That said, if an SJW proclaims that racism is what occurs within a context of oppression and therefore is not significantly problematic when practised against privileged groups, it is fun to be able to argue that they are not only wrong but have precisely the opposite of the truth.