St. Thomas also taught that an invincibly ignorant person who sought the truth with an upright conscience, would receive what was necessary–at the very least by an interior illumination on their deathbed or by the instruction of an angel.
St. Thomas believed the bear minimum truths that needed to be known was the Trinitarian nature of God. A much small number of theologians taught that every dogma of the faith must be known.
I don’t know of any theologian who taught that every dogma would need to be known. That is obviously false. According to St. Thomas and St. Alphonsus (and probably most of the others), what must be known
explicitly is that 1.) there is one God, who 2.) rewards the good and punishes evil, is 2.) a Trinity of Persons, and that 4.) the second person was Incarnate.
The other dogmas only need to be believed
implicitly, which means they are not rejected and would be believed if the person was aware of them.
However, more common and what seems to have been adopted by the magisterium is knowledge of one God (which would be least possible knowledge, since you have to believe in God to have divine faith and God can be discovered through natural means).
But no matter where one’s opinion lies in this regard, there is practically unanimous agreement that an invicincbly ignorant person is not automatically damned,** but that God in some way would make those necessary truths **available to them at somepoint before their death.
But if God made the “necessary truths” known to them prior to death, they would no longer be ignorant of them.
If you read what you said, it appears that you are saying a person would not be saved if they died invincibly ignorant. They can only be saved if the “necessary truths” are somehow made known to them… which is exactly what St Thomas said.
As you said above, St. Thomas taught that a person who was properly disposed would receive the “necessary truths”, either by a missionary, or possible an angle, or if nothing else via an internal inspiration. That makes the most sense to me because “withouth faith it is impossible to please God”.