Hi Paul, welcome to the IBT forum.
Odd that your dreams should stop when using IBT. The majority of people report increased more vivid dreams, even lucid dreaming and remembering their dreams. Though having said that, I can go for weeks perhaps months without remembering my dreams, or indeed whether or not I have dreamed.
Your lower pressure analogy fits with the IBT theory, as the upper most part of the tube filled experiments has the lowest pressure and can be observed in soft walled tubing to collapse the wall.
Re lungs Pleural Thickening. I do know of an elderly man who was exposed to asbestos when young and diagnosed with asbestosis, who sleeps inclined. He is short in stature so there is no connection with height in this instance. His long standing coughing problem has been easing over the last few years using IBT, it is almost as if, dare I say it, his damaged lungs are recovering, I have not heard of this problem occurring in tall people before, but as most tall people would definitely not be inclined, it seems counterintuitive that this is occurring because you are inclined? Are you a smoker or have you been exposed to pollutants such as asbestos or paint spray etc?
Muscle growth has been shown to occur where a medical condition normally atrophies the muscles and heart, using IBT. According to how circulation is affected by gravity, the heart and lungs are not working harder and against gravity, but working with gravity, so are in effect under less strain than sleeping flat. Muscle density also increases according to reports. Have you noticed muscles firming up using IBT?
Thanks for your post and hope this helps somewhat.