3 Nephi 19:29 and the "oneness" of the Godhead

In the Bible, the "oneness" of the Father, Son, and Spirit is clearly not a metaphysical/ontological "oneness" of being, as formulated at various councils such as Nicea, Constantinople, Ephesus, and Chalcedon; instead, it is a covenantal oneness, similar to the "oneness" that Jesus wishes for believers to have with the Father:

That they all may be one (εν), as thou, Father, art in me, and I in thee, that they also may be one (εν) in us: that the word may believe that thou hast sent me. And the glory which thou gavest me I have given them; that they may be one (εν), even as we are one (εν). (John 17:21-22)

In the Book of Mormon, one finds various "oneness" texts, but it would be fallacious and eisegetical to read into such texts (e.g., 2 Nephi 31:13, 21) is not the Latin/Creedal Trinitarian understanding of such, but the same type of "oneness" explicated by Christ in John 17:21-22, consistent with a form of Social Trinitarianism. That such is the case can be seen in 3 Nephi 19:29, which should serve as a "controlling verse" for Book of Mormon theology:

Father, I pray not for the world, but for those whom thou hast given me out of the world, because of their faith, that they may be purified in me, that I may be in them as thou, Father, art in me, that we may be one, that I may be glorified in thee.

For further reading:

The Number of God in the Book of Abraham and Alma 11

Examples of Non-Trinitarian Statements in the Book of Mormon

The theology of Alma 11:44

LDS Christology and John 10:30 and 14:10-11