Not everything turns out, that is an experiment.
In my several decades of figuring out what a story is, I sometimes have taken the approach that almost everything is worth trying. As a writer you cannot know what will trigger the unconscious into action: and triggering the unconscious into action, it seems to me, is one task of the creative sort.
You are attempting to frame thoughts in terms of symbols; and the creation of symbols seems to be a task to which the conscious mind thinks itself equal at least as often it proves itself not so.
In the 1990s I went through periods of excessively fast writing in an attempt to prevent overmuch intervention of conscious thinking. The approach works, at times: it seems suited especially for the creation of imaginative miniatures which are irrational in nature but which seem to have some sort of elemental balance. You cannot expand such stories, or continue them fruitfully at much length: they are what they are. They are like doodles in ink. You can, however, rewrite them -- with difficulty. In the past, several times, I have sent such stories to gather their dozen rejection slips before being capable of noticing some basic errors, missteps or mistakes that might be corrected without doing violence to their symbolic coherence. Sometimes I think stories that contain a considerable number of unconscious elements become partly invisible to the conscious mind, which is the mind capable of doing good editing.
Most often, fast writing leads to meaningless writing. Yet the task I set myself, that of doing the writing and finishing the job at whatever speed necessary, is not meaningless. It expands the possibilities of writing, even if the result of any particular effort might be complete failure.
There comes a point, in any case, when it becomes hard to tell what "slow" or "fast" means, in relation to composition -- for what matters is the degree of engagement.