an Orthodox or a Protestant who knowingly./pernicously rejects Catholic teachings can be saved as long as they were not conscious that denying dogma is a sin

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You can say this claim is idle because a) it is not known if such a scenario is even possible, and b) we cannot read people's minds and therefore cannot know if it even happens anyway.

How would you refute a novus ordite who would say that an Orthodox or a Protestant who knowingly./pernicously rejects Catholic teachings can be saved as long as they were not conscious that denying dogma is a sin in the eyes of the Church? I heard this from Ron Conte when he was trying to reconcile Cantate Domino with Vatican 2. Are the conditions for the mortal sins of heresy, apostasy, and schism of different nature than the others such as stealing something while not knowing it is a sin? If what that dude said was true that would make evangelization of those groups harmful or presenting them with the dogma of EENS harmful.

Dying outside of the Church is the only sin that cannot be forgiven, the degree of culpability only God knows and takes into account when they are judged.

In the next life, all those who died outside of the Church will see with absolutely clarity all those times they rejected learning about or entering the Catholic Church. For those souls, their rejections will replay over and over without end for all eternity and they will know they were  judged and sentenced justly - to their most sorrowful and utter regret.

This is "their worm" that "dieth not" that Our Lord spoke of, which is the pain of loss, which is the primary pain of the damned in hell.