Great stuff, Sean.
I am not so sure we can infer psychophysical dimensions purely from spectral observation.
Especially the assumption that a box spectrum (or gaussian) which gets wider or thinner will elicit a constant hue perception. I see no reason to believe that this is happening in nature, so why would we tune in on that dimension? In nature, when we see the same object more or less pure in colour, it is because we change surface attributes like wetting the surface. Or dust on an object (mixture with unselective particles) will make it appear less pure in colour.
But the spectral toolbox is useful to elicit some physical fundamentals, for example, to define the boundary of matte, reflective colours and light-emitting colours. Here is a video where I use a similar approach to you to determine the boundaries of “natural colours”:
Skip over to 7:15min.
But your work shows nicely how things go through the roof if you throw in another observer 