Why does it require genealogical research, though? Can proxy baptism only be performed by living relatives? And if not, then wouldn't just knowing the name of the person suffice? Or, for that matter, wouldn't any way to unambiguously identify them?
In practice, you just need the name and birth year and maybe another detail or two. And a recent rule does require that members focus on their own ancestors.
But the point of the whole thing is actually to spend time learning and researching your family history. In other words, the literal posthumous baptism is not the point. That's the ritual. It's what to learn and do along the way of accomplishing the ritual that is the point.
