I can relate a lot to these replies, more so the psychedelics/dissociative induced 'delusions/psychosis' (to which I also agree there is signal and noise in it with the potential for spiritual progression when the signal is sifted and integrated) but less so relate to the amphetamine/stimulant psychosis, like never had imaginary spiders etc.
When I have cross the line, which has happened a few times in the last year or two when not respecting 3-meo-pcp's power, it has been everything from receiving signals 'from the top', thinking that I was half Jesus and half the anti Christ embodied which has why my life has been so polar, the Jesus half creating the best if it, and the anti Christ element creating the strife, thinking that I was kidnapped by aliens when waking up from a memory lapse (missing time) and subsequently thinking that the aliens were upgrading my brain/consciousness to be able to handle the next paradigm we have since entered, and then there was the time a few no the ago where I concluded that we are living in a simulation, and that people take this shit too seriously, like, this is just a test or training ground not even the real thing! Either that, or it really is meaningless and we are just programs running in some aliens' quantum holographic computer, and they are having a laugh about it.
High doses of MXE would also take me to a place where I feel I was piercing the veil and allowing extradimensional entities or spirits to communicate with me, or allow me to receive signals from the moderators of the matrix (same simulation theory stuff).