W.W. Phelps vs. the claim early LDS Christology was that of Modalism

In a letter addressed to Oliver Cowdery, W.W. Phelps wrote:

What a glorious prospect appeared after the angel delivered his message! The heavens had been opened; the gospel again committed to men, and a period as great as when the Lord said unto Abram, "Get thee out of thy country, and from thy kindred, and from thy father's house, unto a land that I will shew thee. And I will make thee a great nation, and I will bless thee and make thy name great; and thou shalt be a blessing: And I will bless them that bless thee, and curse them that curse thee; and in thee shall all the families of the earth be blessed," welcomed the beginning of better days in the midst of this crooked and money seeking generation. For, as the angel informed our brother Joseph, that the Lord was about to proceed to do a marvelous work among this people, that Israel might be gathered and saved, so also was that glorious day shown when the Lord should come the second time to dwell on earth; yea, even come in the clouds of heaven, with all his holy angels with him, to execute judgment upon all, that the earth may rest; that righteousness may abound; that all flesh that is justified, may glorify God and enjoy his presence a thousand years.

Though, at the time the heavenly messenger came down to open the understanding of a few, and prepare the way for the true church to arise, and come forth as it were from the wilderness; yea, though at this time, the fathers had fallen asleep, and all things, seemingly but the gospel, remained as they were in other ages, and men that pretended to worship, did it as a mere matter of form, without authority or power, yet the "strange news" was believed by some, and hailed as the harbinger to prepare to gather the Lord's elect; and in fact it was the day break of a day of glory.

I was not a professor at the time, nor a believer in sectarian religion, but a believer in God, and the Son of God, as two distinct characters, and a believer in sacred scripture. I had long been searching for the "old paths," that I might find the right way and walk in it, and after a suitable time to investigate the work, and prove its truth by corresponding evidence from the old bible, and by the internal witness of the spirit, according to the rules of holiness, I embraced it for the truth's sake, and all honest men who seek a better world, will "go and do likewise." ("W.W. Phelps, Letter No. 7," The Latter-day Saint's Messenger and Advocate, Vol. 1, No. 8 [May 1835], p. 115, emphasis added)

What is important here is that Phelps, before converting to the Church (he was baptised June 1831), he held firmly to the Father and Son being “distinct characters”; in other words, he opposed Modalism, and he found such a teaching among the Latter-day Saints.

I highlight this as it is a common claim by some (e.g., Dan Vogel) that the Christology of the Book of Mormon and other early LDS publications is that of Modalism, wherein the Father and Son are one and the same person (or “character” to use Phelps’ terminology), notwithstanding that this shows the opposite to be the case.

Update: I have noticed some misinformed individuals arguing that Luke 10:23 (JST) and other like-texts, as well as the 1832 First Vision account refute this post. All it proves is that many critics have a poor grasp of exegesis as well as being ignorant of LDS scholarship and apologetics. For a refutation of JST Luke 10:23 as a "proof-text" for Modalism, see Does JST Luke 10:23 teach Modalism? On the 1832 First Vision account, see The 1832 First Vision Account versus Modalism and Psalm 110:1 and the two Lords in the 1832 First Vision Account