If you get a chance to write a post communicating the main points from this in 1/5th − 1/10th the length, I would be (genuinely) happy to read it. As it is right now, I find my eyes keep glazing over as I read this. If you do write a shorter version, please let me know, because as someone who often has trouble sleeping myself, this is of interest to me.
tl;dr: By focusing in a counterintuitively alert way on your hypnagogic hallucinations you can use them as a sort of biofeedback mechanism, following them as they change their characteristics in predictable ways in a direction that leads you out of insomnia into sleep.
alternatively: By reading this prolix description of hypnagogia, your eyes will glaze over until you find yourself nodding out.
And after the tl;dr summary, skip to the guidepost section which is actually fairly short.
Maybe useful to put the TLDR at the top of the post? I had a similar reaction to MikkW and was originally intending to save the link to possibly read at some later time. But then I was lucky enough to start skimming the post instead, getting a good chunk of value. Would have done that for sure if there was TLDR that gave some more guidance.(Great and well-written post-overall.)