Jacqueline Stone quotes a dialogue between the Tendai Priest Enjitsubo Hoin Jikken and one Hongaku Hoin Nichidai (1309-1369) in 12/23/1363 and 1/26/1364. Nichidai recounts that Jikken informed him
"On this mountain [Hiei], there are no longer any learned scholars. I am fourth in line of transmission from Shunpan. This lodging Temple was formerly the site of Shunpan Hoin's Goma Hall. The leadership of the Eshin school rests with me."
Jackie then recounts that Nichidai replied:2
"The great Saint"1 (Daishonin -- note the flavor of the Fuji school even at this early date) "inherited the Tendai Doctrine from Shunpan, I am fourth in the line of those who propagate this sect. Is the Tendai Transmission which the great saint received the same or different from the Tendai transmission that you uphold in this lodging temple where I have encountered you?"
"We exchanged opinions, What a mysterious Karma."
In this day and age Nichiren Shoshu maintains that the Gosho are the product of the Priesthood-Sangha and that works authorized by an "enlightened" high priest are just as worthwhile study material whether they can be documented as such or not. (QA56 of the Questions and Answers of the Sokagakkai Issue). This also leads them to "Secret Transmission" or "Kuden" style interpretations of not just what Shakyamuni or the sages following his advent say but also of what Nichiren himself had to say. It is a "Hongaku Style" interpretation for example that says that Nichiren said that Shakyamuni was the eternal Buddha but that he was actually saying that he was the Original Buddha who transferred the 5 characters to Jogyo Bosatsu, or that interprets various words in his teachings to mean things that aren't in a literalist interpretation of his words. It is a very "Hongaku" Style interpretation that one reads in the lectures on the Sutra by Josei Toda for instance. Thus what is orthodox to everyone else seems heterodox to Nichiren Shoshu believers, and vice versa because of the "teaching" reversals that originally were part of oral traditions designed to help initiates understand the profound meaning of Nichiren's teachings.