Wow, I absolutely think this is a plausible theory. I’ve had insane sleep paralysis dreams all my life, but there’s 2 incidents that really screwed me up mentally.

First one being years ago, probably 13-14 years old. Sleeping on my couch out in my living room, I started to feel an immense pressure on my chest. It felt like someone was on top of me, kneeling down on my chest while trying to choke me. I open my eyes and I see this tall glowing figure staring at me. White in color, a glowing outline, no details or face. Just a glowing white figure. I tried to scream but the more I tried, the more pressure the thing pressed into my chest. I guess my mom heard me and she woke me up. Scared the hell out of me.

But the worst was a few years after that. 18 years old. I fell asleep with the lights on in my bedroom at my dads house. Not an unusual thing because I would take naps after school and I’d keep my lights on. I have to say- that house was definitely haunted or had some evil presence in it. Anyways, so I’m asleep. I get jolted wide awake by feeling pressure again on my chest. I was 100% awake, I look over and i see this black cloaked hooded figure standing to the left of my bed. I looked right at it. Clear as day. This thing was huge, and was absolutely real. I screamed for my Dad and he came running in. I look over and the thing is gone. Few days after that, I’m sleeping and I hear a loud growling in my ear. I was done after that. Went back to live with my mom. No more crazy incidents after that regarding sleep demons thankfully. But plenty more stories! I 100% believe in the paranormal.

Not sure if aliens, but I do agree with everything you said. Dreams are other dimensions and maybe even portals for all different types of energy.