I'm very interested in eschatology, and I read texts from Catholics, the many flavors of Protestantism, Native Americans, even Muslims, searching for the truth. Joseph Smith said we don't have a monopoly on the truth, and that we should seek it out everywhere.
Joseph Smith said that ... he couldn't find the truth in any of the denominations of his time ... that they all taught abomination ... and so God called him to restore His truth.
Did Joseph have a change of heart ?
All true Christians have a change of heart.