This kind of fast and furious writing is along the same lines as freewriting, which I have been a proponent of for years as a means of unlocking the subconscious, allowing ideas to flow freely and without censorship. Writing guru Natalie Goldberg (who calls it writing practice or automatic writing) describes this type of writing as a “crack through which you can crawl into a bigger world, into your wild mind” (p 40, Wild Mind).
The longer I write, the more I'm convinced that the only way I can write a novel is by free wheeling it. That is, using various forms of brainstorming and free writing to complete the first draft.
Currently, I'm using the free wheeling approach to write a couple of short story series too. It works for me, and it works for my short story coaching students. One said: "I've finished five stories in the time it usually takes me to write a single story..."