So, we have two sides of approach, that science never get to really bring in harmony together (make me think of Jung and Pauli trying to find the ultimate explication for synchronicity and quantum physics) :

* Psychological - autosuggestion, set and setting , the colour of the pill, advertisement, energy transfer of the practicing chemist

* Physical - dosage, impurities, improper synthesis, natural or synthetic precursors, other compounds

I think that it is important to  keep that in mind, to don't get lost in the discussion.

The first one ist a lot about empirical experience, and even if certain aspects can be quantified with trip reports, consecutive bioassaying and so on, it can never reach the sphere of objectivity. We all know this. It is still the most important factor to take into consideration since we are all just direct experienced beings.

The second aspect can be analysed by the means of chemistry and the account of practicing chemists who share their experiences. Here we can work on something: making TLC, HPLC and other approaches of analysis, looking in the existing literature of ongoing analysis done by harm reduction labs and historical research.

Couldn't we get some of the still living chemists, to only name the famous ones like Pickard, Nichols, Casey Hardison or Tim Scully (I still wait for his ultimate book on underground chemistry) to share their thoughts with us? Somebody for a contact?

Both aspects are important since they are the sides of the same coin, the microcosm and the macrocosm. But the approach to understand them cannot made be with the same methods of investigation.