I'm not convinced. Maybe phosphene hallucinations are something that a larger population of people can relate to, including possibly the author, and so it is somehow assumed that they derive a bunch of mythology from entopic geometric abstractions? I think that for those of us experienced with truly visionary plants and medicines, that it is more than obvious that full visionary eidetic scenes are accessible to the senses, and it seems illogical to associate them with phosphene phenomena when practically of the ancient cultural evidence that is listed would suggest the exact opposite. At the beginning of the paper, the author dismisses syrian rue cause it's visionary...makes no sense. If anything that should make it fit the bill even more because it is capable of inducing the visions as described in the texts as opposed to the opposite, more simplistic and fundamental visions on the surface of consciousness that would require a lot more creative symbolism embellishments in regards to the ancient scribes as opposed to a relay of perceived stimuli. Honestly, if you didn't read the author's commentary, you would think the paper were trying to assert the opposite.
I'm not arguing that meditation doesn't increase phosphene visions...in my experience it certainly does...and I woudn't argue that it couldn't be taken further than what I've seen via meditation as I'm sure it goes way deeper...however if there is a cross-over to eidetic photo-realistic visions, then it renders talk about the phosphenes sort of pointless.
"Science without religion is lame. Religion without science is blind" - Albert Einstein
"The Mighty One appears, the horizon shines. Atum appears on the smell of his censing, the Sunshine- god has risen in the sky, the Mansion of the pyramidion is in joy and all its inmates are assembled, a voice calls out within the shrine, shouting reverberates around the Netherworld." - Egyptian Book of the Dead
"Man fears time, but time fears the Pyramids" - 9th century Arab proverb