Stop twisting Pope Pius IX's words
Pius IX DID NOT teach that those ignorant will die ignorant. I don't know how many times this has to be said:
Pius IX says that it is a "very grave error" to "believe that it is possible to arrive at eternal salvation although living in error and alienated from the true faith and Catholic unity. Such belief is certainly opposed to Catholic teaching."
He then speaks about those "struggling with invincible ignorance about our most holy religion"...i.e. those living in error, alienated from the true faith and Catholic unity! Those who cannot attain salvation as they are
He then says those observing the natural law, ready to obey God, and living honest lives are able to attain eternal life "by the efficacious virtue of divine light and grace". Again, if you believe EENS you will take this to mean that God will provide those moral "invincibly ignorant" with the opportunity to hear the Gospel (divine light) embrace the faith and enter the Church (divine grace through baptism)
Your last sentence is just silly. That is not what Pius IX is talking about. You are interpreting the Pope (incorrectly) as saying that the people he refers to will become Catholic before they die.
Here again is what he says in that section:
7. Here, too, our beloved sons and venerable brothers, it is again necessary to mention and censure a very grave error entrapping some Catholics who believe that it is possible to arrive at eternal salvation although living in error and alienated from the true faith and Catholic unity. Such belief is certainly opposed to Catholic teaching. There are, of course, those who are struggling with invincibly ignorance about our most holy religion. Sincerely observing the natural law and its precepts inscribed by God on all hearts and ready to obey God, they live honest lives and are able to attain eternal life by the efficacious virtue of divine light and grace. Because God knows, searches and clearly understands the minds, hearts, thoughts, and nature of all, his supreme kindness and clemency do not permit anyone at all who is not guilty of deliberate sin to suffer eternal punishments.
Pius IX describes two groups of people.
Those Culpably Outside the Church: He speaks of their "living in error" and says they will not be able to "arrive at eternal salvation" while "alienated from the true faith and Catholic unity." So he is speaking of the destination of souls outside the Church after their deaths in this section.
Those Inculpably Outside The Church: He describes people unlike the first group, "those struggling with invincible ignorance." He then describes those people while they are alive, as "observing the natural law" and living "honest lives" which will allow them "to attain eternal life" (not Salvation) by the "virtue of divine light and grace." Noting that these people will not "suffer eternal punishments" if they are "not guilty of deliberate sin." Again, he is clearly speaking for the destination of these souls outside of the Church after their deaths.
Now, it is logically impossible to claim that those people discussed in the second section (the invincibly ignorant) are NOT outside of the Church when they die. Why? Because they are described as "invincibly ignorant of our most holy religion." Both groups of people described are outside of the Catholic unity. Neither group is Inside the Church at their death as you try to claim.
So, both groups are non-Catholic and die in that state. But the first group dies in a state of culpable "error," while the second group dies "not guilty." Again, this make perfect sense because, although both are not Catholic, the first group cannot "arrive at eternal salvation" because of its culpable error, while the second group can "attain eternal life" because they are not culpable.
And you still haven't answered by question that I have now asked you at least 4 times: Where do the "invincibly ignorant" who die Outside the Church go immediately after they die?