I found a scholar's paper on the title issue, and much more detail on the complicated history of the text and questions of authorship:
https://www.academia.edu/3737378/Was...%ABnhu%C3%A1ng
On the question of Kensho:
Already at the time of Dogen's visit to China, Koan Introspection Zen, and the teachings of Rinzai Lineage Master Dahui with their emphasis on attaining a "Kensho" experience, was quite strong. It appears that that was what Dogen was rejecting. At other places in his writings, Dogen makes it clear that seeing the nature (a "seeing" beyond "seer" and "seen"), awakening, realization is vital to him and our practice too. Our way would not be "Zen" otherwise!
Francis Cook, another scholar and translator of Dogen, puts it this way ...
Another bit of trivia: The name of our lineage, "Soto" ("Caodong" in Chinese, 曹洞) is now thought to actually derive from a combination of one name for the 6th Ancestor Hui-neng as "Sokei" ("Caoxi" - 曹溪), the name of his temple in South China, and Master Tozan (Dongshan, 洞山), who is considered the root of our Soto line. So, we are actually the "Huineng-Dongshan" Lineage. (There was another theory that the "So" of "Soto" referred to a relatively minor student of Dongshan, but for various reasons that explanation makes little sense).
I had the opportunity to sit a Sesshin in China at the Six Ancestor's temple at Caoxi a few years ago, where I encountered his mummy which is still there (although it has been greatly restored a few times over the centuries) ...
Sorry to have run long about long ago ...
Gassho, J
STLah