cuм Ex is overrated in the Sede world. It was not a doctrinal declaration but rather a juridical one and was abrogated by the 1917 code of Canon Law. I believe canon 188.4 makes reference to it, but it is no longer a binding docuмent legally speaking.
Yes this. And I don't remember exactly how he put it but in one of his talks, Fr. Hesse said that cuм ex was not at all what the sedes make of it. He gave as an example Pope Leo XIII who made Anglican priest John Henry Newman, a cardinal - which directly contradicted cuм ex.
Then there is also Pope Pius X's 1904 Constitution Vacante Apostolica Sede...
"29. No Cardinal, under whatever pretext or cause of any excommunication, suspension, interdict, or other ecclesiastical impediment, may in any way be excluded from the active and passive election of the Supreme Pontiff; we suspend these same censures and excommunications only for the effect of such an election, while they otherwise remain in force in their full effect."
[...]
"Notwithstanding, insofar as may be necessary, the Constitutions and Apostolic ordinances issued by Our predecessors, the Roman Pontiffs,
which all and each we declare to be abrogated, as above, and likewise any other contrary matters whatsoever that deserve individual and most special mention and derogation.
Therefore, no one among men may infringe this page of Our constitution, ordinance, abrogation, order, binding, admonition, prohibition, command, or will, or dare to oppose it with reckless audacity. But if anyone should presume to attempt this, let him know that he will incur the indignation of the Omnipotent God and of His blessed Apostles Peter and Paul."