Sins only forgivable by pope
Hi! Non-Catholic here, very interested in Catholicism. I was reading that there are some sins that are only forgivable by the pope himself (such as Host desecration, breaking the seal of confession, physically assaulting the pope, etc).
However, I also read that the Sacrament of Baptism removes all sins committed prior to the baptism, as well as the punishment due to them.
So, let's say you have a baptized Catholic, and they desecrate the Host or attack the pope. The only way for them to be absolved of their sin is for the pope himself to forgive them.
However, let's say you have a non-Catholic, who desecrates the Host, or beats the pope. Then, they goes on their merry way, and a few years later, they have a change of heart and get baptized into the Catholic church (lol assuming they got away with attacking the pope and not going to jail). Are they completely absolved of all sins, including the ones normally that only the pope can officially forgive?
As a real world example, I am thinking of Mehmet Ali Ağca, who tried to assassinate Pope John Paul II in 1981. Obviously, Pope John Paul II was a great man so he later forgave Ağca and even met with him in person, but Ağca actually converted to Christianity of his own volition after serving his prison sentence. Assuming his conversion was sincere, did he even need the pope's forgiveness at all? Like if hypothetically the pope decidedly did not forgive Ağca, would that conversion have been good enough?
Anyway, if this is true, why are Catholics then seemingly judged harsher than non-Catholics? If Ağca had been Catholic at the time of the assassination attempt, he would have needed the pope's forgiveness, but because he was non-Catholic, he technically didn't need it and just needed to convert to absolve him of that sin.
Thanks!