As far as Quo Primum goes it's actually moot point, because contrary to the sedes in this thread, we know with certainty that Quo Primum was never abrogated, if for no other reason than because pope Benedict XVI told us that Quo Primum was never abrogated in his Motu.
Yes another dishonest red herring, along with a begging of the question. This thread has nothing to do with Ratzinger but the hypothetical question of whether a legitimate Pope in principle could make an addition or change to the Canon despite
Quo Primum ... and not whether Montini et al. had abrogated it. You also beg the question that Ratzinger was even the Pope and that he was telling the truth rather than making the statement as a tactic to suck Traditional Catholics back into the Conciliar Church (as Ganswein later admitted he had intended to do). That's why the OP used the hypothetical example of a Pius XII, to take that consideration off the table. Whether a Pope HAS abrogated
Quo Primum, or rather attempted to, is entirely beside the point. What we're debating is whether a Pope CAN abrogate it. But it's one distraction after another, one dishonest logical fallacy after another, in a pathetic and desperate attempt to cling to the notion that you aren't wrong. You clearly are.