I think they treat Joseph as a "fallen prophet" to some extent, by virtue of the fact that they don't accept Joseph's plural marriage teachings. They don't even call themselves the "reorganized" CoJCoLDS any more, if I understand correctly.
The first edition of the Doctrine and Covenants was published in 1835 at Kirtland, Ohio, nine years before the death of Joseph Smith. The second edition was published at Nauvoo, Illinois by John Taylor in September of 1844, about 2 months after Joseph’s death. All of the passages which are quoted from the Doctrine and Covenants in this essay were found in both of these editions. To the contrary, there were no passages in either of these two editions which affirmed the belief in the theory of eternal progression or multiple gods. All of the questionable material which has been attributed to Joseph Smith on these subjects did not appear in any edition of the Doctrine and Covenants until the Utah Mormon edition of 1876, over 32 years after Joseph’s death.