Cool stuff @SeanCooper! I will take a better look at your notebook (hopefully before the next meeting).
Looking quickly and diagonally at it, I realise that maybe we should have an argument to generate the pulse waves in a way that is better for representing the hues in that definition: https://github.com/colour-science/colour/blob/c8acc31a8507dae1af81d7958490ac3428dc2728/colour/volume/spectrum.py#L57
It essentially does a similar job to your optimal_colour_stimuli definition but while generate_pulse_waves is built to generate the whole surface at once, the triangle base will prevent generating the hue lines like yours.
Typical flow for CIE xyY:
It gets very pretty with CIE XYZ! I will try to see if it can get an alternative flow in.
Cheers,
Thomas