I created https://news.ycombinator.com/item?id=49469365 to see how many people perceive things this way.

It is quite possible that this is drawing a line, as you say, between hyperphantashia and regular phantasia, though I'm not yet willing to give up on the idea that we are just giving subjective names to the same phenomenon.

To wit, when I "hear" things with my "mind's ear" I can "hear" them very well in all the layers and components, I can "hear" drums and guitar and bass and voice, etc., but they are very clearly in my head -- they do not have a location in real space the way that real sounds do; I can't "hear" a sound so loud that it makes me cringe or so quiet that I have to strain to hear it.

In case you missed my other comment linking to similar polls and stuff on Reddit: https://news.ycombinator.com/item?id=49469522. The hyperphantasia subreddit covers all other sense imagery too, and I am high on all of them.

Also, to be clear, my images usually are NOT spatially located, but I can choose to make them so if needed, and occasionally they just are spontaneously.

You might also find the work of Louis Sass ("Madness and Modernism", and other works) to be relevant, as he notes it is extremely common for schizophrenics to always be localizing (sensing) their thoughts have specific locations in space, or e.g. are "moving from the front of my head to the back", and other such extreme (and arguably unhelpful) spatialization of aspects of the mind's eye. He argues this might be part of why they are prone to hallucinations and delusion.