I enjoyed your piece on Kekule's Ourobouros -- thank you for sending it.
And I'm glad you've demolished his "dream": surely it was a "reverie"; and I concur with your observation
about dreams being unimportant.
The half-wake state is another matter -- I find that a common experience. My interpretation is that the underbrush is cleared
away (perhaps by prior dreamwork) and it's an excellent time for a fresh start, new directions, on a problem.
Carl Djerassi figures an example in his novel, Cantor's Dilemma.
Have you noted Judson's "Search for Selections" (1970)? And "Mind's Eye" is a title of a book on Engineering
Design that I've seen.
"Brainstorms" may describe a related psychological (hypnogogic?) state. I've seen a few books with that title
-- but you probably know that literature very well.
P.S. Creativity is not just unfettered imagination; it entails the appropriate reality-grounded criticism as well.