This is a great post. Thanks for sharing.
I have not experienced 3D immersion per se, but I have often forgotten where I am and my own position of seating while reading some novels.
I remember while reading The Matarese Circle by Robert Ludlum, there is a section that builds up a tense atmosphere where an American spy and a Soviet agent come face-to-face, and fight. I remember that I attempted to ‘block’ a blow by the American agent because of which the book fell from my hand, which is when I realised that I was merely reading a book.
Needless to say, Ludlum has remained my favourite spy fiction author since.