Pablo could you, or perhaps some other kind forum reader, provide a brief explanation of what they actually do? The abstract more-or-less says ‘we solve a problem’, but it’s unclear exactly how they solve the problem—I have no intuitive purchase on what “more inclusive formalizations” means—so don’t know whether it’s a good use of time to read the paper.
The main result extends the RC formalization to versions that include an unaffected part of the population (such as dead past people) and shows that all Aggregative social welfare functions that satisfy basic axioms that are uncontroversial in the population economics literature imply this. That includes, for example, average utilitarianism, number-dampened utilitarianism, average and total prioritarianism and egalitarianism, and many approaches commonly understood to escape the RC, including all same-number separable approaches. Of course, what makes it the length of a paper is talking about why this makes sense in the literature! We also have an extended result that covers an even larger set of social welfare functions.