Never read that about FF in the "MBR." But it is true that he spoke many languages. I remember that he went to the Spanish KH -besides his fluency in other languages. It is also true that he could quote much of the Bible (Psalms for example) by memory. He did not uses notes, or rather, he did not need them for his talks but neither did NHK. Never once did I see NHK refer to his notes, or he would just give any talk without any notes even at the assembly.
As far as the MBR, one day while I was visiting Costco, I looked at the MBR at their book section. What I read in the book was that JW had the record for receiving the tiniest blood transfusion in the world consisting of only blood fractions. I figured it out that the authors were just making fun. They also said something about the "truth book" being the 2nd most published in the world but it was also in jest.
But the farther away from HQ the more the JW would deviate from standard. Close to HQ , the man was respected but any glorifying remarks about him to others in the presence of an elder, etc, would get a rebuke as a reply. I think that he was a brilliant man; much of the WT ground works for understanding the Bible was his thinking, I was told, but so was 1975, and the end 6000 thousand year after Adam teaching. I cannot see the MBR saying something about him though without jest, so if they mentioned him as one of the most intelligent, they probably qualified that with some joke -but you read it and you know what you read.