All of these add plausibility to the historicity of the Book of Mormon with knowledge that wasn’t accessible in Joseph’s day.
President Howard W. Hunter made an interesting statement related to Book of Mormon geography quoted in a Deseret News article in 1995
it’s pretty clear that the Promised Land extends from North America to South America. The United States is the Promised Land. Mexico is the Promised Land. Brazil is the Promised Land. Etc.
These two quotes demonstrate how apostles are open to a smaller geographical size for Book of Mormon lands, rather than a larger size.