Nice thread, gentlemen!
As to "machine", I have experienced this many times behind shrooms, LSD, DMT, even MJ

Well, even when I was "sober", too

Appears to be somewhat like common theory, don't you think so? With many variations, of course, but it's just the same in it's core - our perceptive systems with all their complexity are just some let's say "parts" of a "bigger system" of more complexity.
I can not say 100% for sure now, but more likely I ran into it with the "help" of LSD for the first time. It was great experience, but in it's part devoted to the topic I began to feel like I was a victim of some global experiment in which my individual perceptive system was under control in entire universal perceptive system, which was just "the working model"
designed and built particular for this experiment. I could see persons (I percieved them as humans then) who were making different manipulations on my psycho-somatic complex to make me perform in some sort of an artificial existence, which I percieved as my "common life" normally. And I knew that those persons knew that I knew, etc.
I will skip all philosophical speculations to save your time now. Just will say that it was a horrible existential nightmare

And of course, I thought it will last "forever". But as there's a ballance in everything, after some time I began trying to find an escape. I found it after an idea came to me that now I know "the truth", and there's no reason to be mad or sad about it. OK, it's not rewarding our sense of being THE KINGS, but it could grant us w/one more little step to "freedom". After that many visions of my karmic deeds came (in symbolic form). I saw that I was acting like a blind fool (OK, like a blind part of experiment) and I managed (it will take a long time to describe how) to destroy those karmic aftermaths. After that I could feel much energy in all my
bodies, lately this energy helped me to change many things in my "real life"

BTW (attention here, you paranoic folks!), I could feel "experimentators" were aware about it! 8)
Visions of that kind lately formed a huge part in my psychedelic experience with any substance involved. It varied in details - like it was different "aliens" (sometimes friendly and sometimes not); some kind of "powerful astral beings"; "advanced post-humans" who were experimenting, and there were many other possible pholosophical interpretations as well, but it was the same in it's core - we are just "small parts of the machine" and nothing more
by far.
Well... IMHO, this "machine theory" is funny and promising just like any other theory, which can possibly add something to our attempts to know and to integrate ourSELVES :roll:
GOOD LUCK for all of you, space travelers of your MIND! :d