The story is bunkum. There is no such language as "reformed Egyptian," and Smith's translation ability was proven to be total nonsense through his faux translation of the "Book of Abraham." This document was later proven to be a funerary tract, having nothing to do with Abraham, and written more than a thousand years after Abraham lived. The silly group of toadies who claimed to have seen the golden plates have mostly been neutered through later admissions and disavowing.
People who actually think about reality have determined that given the specific gravity of gold and the length of the BoM, the plates would have had to weigh at least a hundred pounds, which is totally inconsistent with Smith's tales of him carrying them around as though it were no heavier than a conventional, paper bible.
When you TRANSLATE a work from another language, you take the original meaning, and re-state it into the target language - in this case 19th century American English. Smith didn't do that. He created a document that employs 16th century British English, just like the King James Version. But Smith didn't understand the niceties of that language, misusing Thee, Thou, and adding "est" to verbs in a helter-skelter fashion.
The "history" set forth in the BoM is totally preposterous. It mentions horses, camels, cows, sheep, none of which existed in the pre-Columbian Americas. He talks of iron swords and breastplates; again, there was no iron in these continents. Same for chariots; the wheel had not yet been discovered in pre-Columbus days. In fact, Brigham Young University has spent more than a hundred years and untold resources trying to find a single archaeological proof of the BoM. Total failure. Nothing. Not a single artifact.
Those who are impressed by little things like genetics have noted that, although Smith believed that Amerindians were the descendants of the BoM Semitic people, but there is no genetic indication that this is the case.
Those who have done even a little bit of investigation know that an early partial draft of the Book was destroyed by the wife of Smith's co-conspirator, Oliver Cowdery. Smith, fearful that Ms. Cowdery was lying, agreed to re-translate the text, but cautioned Cowdery that the text might not be the same as the original text. Why would be do this if he was actually translating, and not making it up?
Nothing against Mormons, but their religion is based on quicksand.