Show us several people that are in this enlightened state right now, thanks to a specific psychedelic. Let's see that there are no downsides, no unwanted changes in those persons' personalities.
The burden isn't to prove that there are no side-effects, just that their rate and severity are sufficiently low.
Have you not met monks, people who have used various drugs, or subscribe to various philosophies/religions? Many have a lot going for them but are also lacking in other areas. Hope you get what I mean.