i found an article (which doesn't appear to address your question, unfortunately).
it's called The Mystery of Hypnagogia
, by DREAM STUDIES PORTAL.
i redacted the link, cuz it's "commercial".
by and large, Hypnagogia appears to be uncomfortable and undesired by most.
the wiki-page says that "People who have spent a long time at some repetitive
activity before sleep, in particular one that is new to them, may find that it
dominates their imagery as they grow drowsy, a tendency dubbed the Tetris effect."