You are correct that the Catholic Church's teachings on salvation have developed over time, and that the idea of "invincible ignorance" has been understood in different ways throughout history. While it is true that the Church's traditional teaching on the necessity of baptism for salvation has been qualified by the recognition of baptism of desire and baptism of blood, the idea of "invincible ignorance" has also been used to describe the situation of those who, through no fault of their own, are not aware of the truth of the Catholic faith but still seek God with a sincere heart. The Church recognizes that the question of salvation is ultimately in God's hands, and that the Church's role is to proclaim the truth of the Gospel and offer the means of grace to all who seek it, while leaving the ultimate judgment to God.