I can't say I looked into bodybuilder's experiences, but I respect it. The report you linked seems highly accurate.
I didn't think I mentioned trying testosterone in the post (insofar as I was living a "high-t lifestyle" in 2019-2020 or so it was all natty) but more recently I have actually tried deliberately spiking my testosterone levels in order to experience the phenomenology. Still experimenting with it and will refrain from immediate comment.
I don't enjoy meditation, so I don't do it often. I never really figured out the move to relax muscles through meditation. (By 'relax' I mean all the way; before I started, my calf muscles were rock solid concrete-like fascial adhesions which took repeated foam rolling and massage gunning in order to deconstruct; they're completely loose now). Once I figured out that this was possible I didn't waste much time procedurally applying it to my entire body.
I definitely think body maps are quite malleable, especially the size and shape of the face in relation to the body and the visual field. This is an exercise I use to demonstrate it.
I have also sat people through acute psychotic episodes a few times over the years, so I'm familiar with what that looks like. I also agree with you that it can be quite frightening and sad.
Schizotypy is not the same thing as schizophrenia or psychosis. I hoped that I was being careful enough with my language around this (and even lampshading colloquial use of the term "schizo" with scare quotes) that nobody would think I was conflating the mild increase in schizotypal traits I was experiencing with schizophrenia or psychosis. I'm not sure how I could convince someone of this through a comment field but having spent ample time around people with these traits I do not model myself as being prone to schizophrenia or psychosis.
I'm also familiar with what both inducing and resolving HPPD can be like. In my experience, HPPD tends to have visual characteristics similar to the psychedelics which induced it. For instance, for a few days after using 2C-B, I'll tend to see strobing afterimages (if I look at my curtains, which have blue stripes, and then close my eyes, I'll see a brief flash of yellow). Estrogen did not do anything at all like this.
I also wouldn't conflate ketamine with psychedelics, and neither would Robin Carhart-Harris! It's a dissociative!
I recommend reading everything Zinnia Jones wrote about it. I also occasionally spend a bit of time trawling through posts on r/dpdr, there's some interesting reports in there.
I would suggest looking at things like three-dimensional space groups and their colourings as candidate glyphs, given they seem to be strong attractors in high-energy DMT states.
This sounds like a shadow talking. I think it's perfectly viable to align the two.
I wish to reiterate that in the original post what I am talking about is schizotypy, not psychosis. These are distinct conditions and should not be conflated.
Additionally, in that comment, I mention that I have a handful of friends who have experienced psychosis. None of these people were rationalists or had anything to do with rationality.