Although Geddes work on loudspeakers includes subjective listening tests and was published and refereed, his work on on amplifier distortion is just a proposal - he carefully and honestly writes "To be useful we must show this metric provides a better correlation to actual subjective evaluations than current metrics." (quote from his site) The tests carried in his paper on audibility of non linear distortions were carried with headphones. His work focused on finding a metrics that correlated with subjective sound considering that THD and IMD have no correlation to the perception of the distortion that they are intended to represent, but was just preliminary and IMHO can't support any firm practical conclusion on relative subjective evaluations .
Cheever work is a Master Thesis, nothing else, we addressed it before in WBF. Anyone reading if fully can see it was supposed to be a starting point, proving he has the competence and capacity to go on more in depth studies. It is outdated, and as we can expect most of the time from a master thesis, superficial in fundamental aspects - no one has time to carry significant work in such a reduced period.
IMHO not enough to support any fundamentalism, unless you carry some listening tests in scientific conditions to pursuit and validate their work - no one except you seems currently interested in their work.