For another class I came across this reference that suggests that my idea is not entirely new in this discourse. Integrating the Jakubiak spectral database - where the measured data is available for reliable generic materials - into the daylight calculations makes sense here.
And in an earlier part of that thread @chris references a potential source of EnergyPlus materials: Material Database for Energy+, Radiance and Therm - #7 by chris
My preference is for web-based measured data that is product-specific (like the International Glazing Database) so that the data sources are transparent in the same way Light Fitting manufacturers have to publish .ies files for light distribution from their products and EPDs are increasingly required for all building products …