I feel like there would be much more obvious practical differences if it was a real thing. The spectrum as described seems so different from one end to the other that we seemingly have people who can switch reality into a movie of their choosing on one side and people who can’t imagine like what a square is on the other. It seems like communication would necessarily have to be very different, books would be different depending on the authors phantasia, UI/UX would be different - it’s hard to believe everything is so homogenous if it’s really serving people with such different visual capacity.