I think it's the opposite of "controversial" to review and support what Joseph Smith, Oliver Cowdery, David Whitmer, Brigham Young, Anthony Ivins, Marion G. Romney, Mark E. Peterson, and others have taught about Cumorah.
My approach to Church history is to consider all the accounts, assume people were generally honest (although highly subjective) and then seek to understand and reconcile inconsistencies. I continually invite comment and refinement. I don't claim I'm right about anything; I only explain what makes sense to me and why alternative interpretations don't make sense to me. I change my mind whenever someone offers a better explanation. (That's the process I used to reject the Mesoamerican theory after having accepted it for decades.)
It's funny that this is considered "controversial" when many of the prevailing traditions are, or should be, the ones considered controversial.
To me, what should be controversial is the common practice among some LDS scholars and educators to reject any historical accounts, scriptures, or statements of modern prophets and apostles that contradict their theories about the Mesoamerican setting. It's the tail wagging the dog, and it's on display throughout LDS academia, media, and artwork.
Even worse is the ongoing effort by the citation cartel to suppress information and opinions that differ from the Mesoamerican/two-Cumorahs theories.
Specifically, here are some things I consider controversial:
1. The ongoing effort by many LDS scholars and educators to suppress and reject Letter VII by insisting that Joseph and Oliver were ignorant speculators who misled the Church. This group includes everyone who advocates a so-called "two-Cumorahs" theory, an "abstract map" of the Book of Mormon, and/or a Mesoamerican, Baja, Panama, Chile, or any other theory that puts Cumorah somewhere other than western New York.
If you're a student at BYU, for example, you are taught an "abstract map" of the Book of Mormon that declares Cumorah is not in New York, which in turn teaches that Joseph and Oliver were ignorant speculators who misled the Church. It's difficult for me to imagine a more controversial teaching, yet every BYU student is required to learn this.
2. The ongoing effort by some LDS scholars and educators to claim Brigham Young either made stuff up or was recounting a bizarre vision when he related what Oliver Cowdery said about the repository in the New York hill Cumorah, Others besides BY also mentioned it, but just two months before he died, BY spoke about this because he didn't want the knowledge to be lost or forgotten. Yet thanks to the efforts of Mesomania scholars and educators, few members of the Church have ever heard about this.
3. The ongoing effort by some LDS scholars and educators to impose imaginary "requirements" on the text and to find "correspondences" between Mesoamerican culture and history on one side, and what they think the Book of Mormon text should say on the other. These imaginary "requirements" include such things as volcanoes, which are never even mentioned in the text but, according to the Mesomania scholars and educators, must be found in any proposed Book of Mormon setting. The "correspondences" are illusory, IMO, because they are features of most human societies. Many of them are based on the spurious "Sorenson" translations summarized by horse = tapir and narrow neck of mountainous wilderness.
My approach to the scriptures has been to understand the text of the scriptures (BoM, D&C, PofGP, Bible) from the perspective of those who wrote them. For example, the idea that the "narrow neck" would be Panama (or, worse, the Isthmus of Tehuantepec) is purely a modern construct, based on modern maps of the entire western hemisphere.
If it wasn't such a serious problem, I would find it funny to have people determining, by "consensus," what a "narrow neck of land" must mean--especially when the only real consensus among these scholars and educators is that Joseph and Oliver didn't know what they were talking about. This is how the Nicene creed was developed.
The next time someone tells you that Letter VII, the two sets of plates, the New York Cumorah, and/or the North American setting of the Book of Mormon are "controversial" topics, ask them about the three I listed above.
And that's just for starters.