This is interesting and I wonder if it might explain some apparent cases of aphantasia. Also seems relevant to some aphantasics experiencing mental imagery when using psychedelics.
When I took psychedelics they were still in effect when I went to sleep and I experienced unusually vivid and strange mental imagery. They call it closed-eye hallucinations, as opposed to mis-seeing the world around you while your eyes are open, which I also experienced.
I've never experienced visualization under the effect of hallucinogens, but I have once when I took very strong opiates.