3 Nephi 11
33 And whoso believeth in me, and is baptized, the same shall be saved; and they are they who shall inherit the kingdom of God.
34 And whoso believeth not in me, and is not baptized, shall be damned.
40 And whoso shall declare more or less than this, and establish it for my doctrine, the same cometh of evil, and is not built upon my rock; but he buildeth upon a sandy foundation, and the gates of hell stand open to receive such when the floods come and the winds beat upon them.
If “Jesus” is telling The Truth in that section of the Book of Mormon, then Mormons who “declare more” than that "cometh of evil, and [are] not built upon [His] rock, and “the gates of hell stand open to receive such.” An example of declaring more as doctrine would be to declare that Christ’s Church must have a prophet (other than Jesus) at its head, or even a prophet under Jesus as its vice-regent; that one must pay tithing; that one must attend temple rites. And so on.
From the perspective of the Mormon Gospel, no of course not, the Book of Mormon doesn’t have half the things that Mormons believe are intimate parts of the Gospel, and most of the things that the Book of Mormon present as the Gospel, Mormons typically reject through redefinition or simply ignoring altogether, if you count changing the very words of the book ignoring them rather than destroying and replacing them.