ROB explains lack of documentation for JS's early visions, discusses reasons for that.
Ronald O. Barney, "Joseph Smith and the Conspicuous Scarcity of Early Mormon Documentation," in Mark Ashurst-McGee, Robin Jensen, and Sharalyn D. Howcroft, eds. Foundation Texts of Mormonism: Examining Major Early Sources (New York: Oxford University Press, 2018), 373–401
In “Joseph Smith and the Conspicuous Absence of Early Mormon Documentation,” Ronald O. Barney considers three aspects of Joseph Smith’s distinctive leadership style. First, contrary to what one might expect, Smith largely kept to himself the sacred experiences that bore on his divine authority as a religious leader. Second, he refrained from inserting himself into the public sphere by literary means, even among his own people, when it was his prerogative to do so. Third, Smith appears to have had an aversion, or at least little to no interest, in having his numerous sermons captured and distributed. When taken together, these considerations suggest clues to his personality that complicate the view, taken by some, of Smith as a person preoccupied with chronicling his own experiences in order to bolster his credibility as an authentic religious personality.