Hey folks, remember the original question, the history of this thread, and the purpose of the readings.
It was a clear enough question as far as I understood it. Something along the lines of: "Can an incident meter be used to measure the scene brightness range (a.k.a. required exposure latitude) when the scene includes bright reflections (I'll avoid 'specular' because it seems to mean too many different things to different people) from surfaces that we wish to maintain detail in (ie we don't want them to blow out)?"
It's an easy enough question for me to answer for myself, because I carry both incident and spot meters, or a combined incident and spot meter - so I frequently use both types of measurement. Both types have their limitations, but Minor White and Phil Davis (among many others, no doubt) have both given perfectly sound reasons why incident metering can be used for the zone system, as long as you understand the assumptions and limitations. That applies to everything - including the adoption or abandonment of the Zone System itself, surely?