As a result of my "research", LSD remains one of the few recreational drugs that I might ever consider trying in the future, given the correct circumstances.
It is certainly less harmful than nicotine, ethanol, and acetaminophen. But now that marijuana is legal in some states, I expect that it will soon displace LSD-25 as the least harmful recreational drug that I know about.
If you are also curious, my conclusion was that LSD-25 is probably present in AUM at a psychoactive, but non-hallucinogenic, dose, mostly as an adjuvant for the other ingredients. It would help bridge the gap between a drug known to have powerful, positive, short-term effects and one known to cause long-term but very unpredictable changes in behavior.