.......Also- he's used DMT, so he had no real impartiality.
That's a bit unfair swilow. We humans are seamlessly embedded in the reality we choose to divide up and categorise scientifically. A search for "real impartiality" as you define it could exclude important subjective data and exclude the majority of researchers from very important fields of study.
Do we only accept research findings on alcohol from workers who have never imbibed? Or psychological musings on the effect of TV/videos etc from researchers who have never seen such technological inventions or particular programme types?
I grant you that the intensity of psychedelic experiences must undoubtedly "flavour" the approach and cogitations of a researcher, but science is just an
approach to understanding events/experiences, in a world we socially construct as we go along and not the
whole picture. This is especially so when the effect of such an experience has a profound and direct impact on human consciousness (as opposed to say, research on simple tastes or smells).
Science can provide a substantial, but incomplete version of affairs in which it is interested, but the very restrictions imposed by scientific method (e.g. to remove subjectivity) render experiments involving consciousness to an extent quite incomplete.
I would be very suspicious of workers who hadn't tried a particular substance drawing major conclusions - ecstasy is a case in point. Much of the research has been carried out by people who haven't used it. However, they don't seemed to have managed to eliminate subjective variables such as political expediency/propaganda from there findings, and they are held up by much of the scientific community to be carrying out bona fide research (except for Ricaurte et al of course

).
And this is of course, just my humble opinion and, very subjective

.