Was Jesus praying to himself? No. This is modalism. The father is the son and the son is the father. Surprisingly, mormons have great need to use this polemic on their own book more than the Bible. The thing is rank with modalistic monotheism.

It says Jesus is "the very Christ and the very God." It says Jesus is the "very Eternal Father" "the Eternal God manifesting himself to all nations." He is called the Son because of his flesh, but he assures us over and over he is the father and the son. "The father, the son, and the Holy Ghost are one God," "is one God," "one eternal God without end, amen."

Alma 11 even includes a discussion about its brand of monotheism. Zeezrom, the stereotypical corrupt lawyer, tempts Amulek to deny a Supreme Being. Amulek retorts by referring to how righteous he is.
Then, Zeezrom asks, "thou sayest there is a true and living God." "Yea, there is a true and living God!"
"Is there more than one God?"
"No."
"Who is it that shall come, is it the Son of God?"
"Is the son of God the very eternal father?"
"Yea, he is the very eternal father..."

The changes to the Book of Mormon were not meant to change the books meaning as much as they were meant to make it more vague, an ass-covering kind of vague. In the confusion, all one has to ask is if Jesus would pray to himself and then try to ignore or spin-doctor literally everything in the one book that was supposed to be the most correct book, the restoration of plain and precious truths that made such apologetics unnecessary.

But the choice is not between modalism on one hand or tritheism on the other. Neither is traditional Christology.

Traditional Christology paramountly assumes the divinity of Christ and seeks to explain this without "confounding the persons" or "dividing the substance." There are three persons with fixed identities who have relationships with each other, but there is one God, one divine substance which all three share in unity.

It's a contradiction that disturbs logic, but in the Greek church that was the whole point. The scriptures both testified that there was one God and revealed that the three different persons were God. Both were true. To ponder the mystery of the trinity was part of drawing nigh to the numinous as a Christian.

It does not do to point at Jesus' intercession prayer and say, look he's praying to the father for his followers to be one as he and his father are one. Trinitarian doctrine is not threatened by referring to the Father and the Son as like each other and unified in will. And this doesn't mean they aren't consubstantial.

An amateur Yankee yokel would-be theologian like Joseph Smith Junior would think the answer had to be tritheism or modalism and that the creeds were irredeemable. He tried editing any reference to plurality even out of the JST. I have a hunch that's why the LDS church only has portions of the JST in their Bible and doesn't ackowledge the whole thing as canonical. It was never finished, they say. But it was.

But then he had a Hebrew class in the school of the prophets and with only 2 or 3 semesters worth of Hebrew he thought himself a know it all. The overtones of plurality in the Hebrew went to his head.

After having done all the reading I've done on this, I don't think Thomas Monson or Jeffery Holland even really know (perceived knowledge) who Mormon God is. Mormon Jesus is more of a disturbing mystery than the old credal Jesus. Talmage pulled Divine Investiture of Authority clean out of his ass. It was an honest attempt at reconciling modalistic Book of Mormon passages with King Follet tritheism, but it's just a mess in the end anyway. You have to try not to think about it if you want to keep your testimony as a TBM.

I can't help but think of King Follet doctrine as I read the 4 gospels or when I notice plural overtones in the Old Testsment. But the latter has to do with the fact that Israelite religion emerged from a Cannanite pagan pantheon. As partial as I am towards being a God someday, I really don't think handshakes and code words and unprotected sex make any difference if such a doctrine ends up being true anyway.