I would say that very, very few “modern” Catholics have any problem with scrupulosity, in that no one believes they can sin anymore, and that everyone is going to heaven. Short lines for confession, yet virtually everyone goes to communion.
CAF participants aren’t really a cross-section. I find that the readership tends to skew more traditional, and in a traditional understanding of Catholicism, moral sensitivity will be what it always has been. Some will be scrupulous. But again, it’s not really a cross-section. You have to have a certain concern for matters of faith to take the time to participate in CAF to begin with.
I don’t know what they teach in seminaries anymore, but I’d say that in the most conservative and traditional seminaries (FSSP, SSPX et al), how to deal with scrupulous penitents is taught as it always was.