I’d love to have an answer to this! As I said this is anecdotal, based on many years of experiences with friends, and the ones tending to have more vivid dreams seem to have more intense trips given equivalent dosage. It became a bit of a pet theory at some point so I ask about it. I wouldn’t be surprised if there’s some confirmation bias or something like that at play, but given the kind of hallucinatory nature of dreams I can also imagine some sort of linked mechanism.
I also rarely remember dreams and despite occasional exceptions wouldn’t consider most of them vivid. So I tend toward heavier dosages :)