Awhile back I bought a high temperature/low CRI led spot light, precisely because it was a higher temp light source than incandescent light bulbs. My “mere impression” from working with this “lower CRI but higher temperature” light source for indoor tabletop still-life photos is that even for black and white output it’s better to use “high CRI but lower temperature” incandescent full spectrum light sources, if these are the only available choices. I retired that led spot and went back to using incandescent bulbs. This was several years ago, so hopefully the same price point now will purchase a higher CRI led.
@chris says that CRI figures are easy to manipulate. My impression is that anything less than 92 (? anyone else have a better figure?) is not good for photography, and the merit of “92” surely depends on how the CRI figure is calculated. I had a pair of CRI 92 fluorescent lights, and the particular bulbs were pretty good. But the CRI 85 LED light was horrible, imho.
I don’t see any way that you can reconstruct information from the missing wavelengths of lower CRI light sources. I think you would need a mathematical way to predict what percent of what wavelengths of light the varying surfaces would have reflected, if the low CRI light source had actually contained those wavelengths so they could have been reflected. I think this means that for low CRI light sources the chances for metameric matches/mismatches for vastly different/same colors would seem to skyrocket. But this is based on deduction, not on experiments.
In terms of emulating low CRI when a photograph is taken under a full spectrum high CRI light source, if you know exactly the spectral output - the weak and strong wavelengths for the low-CRI light source that you want to emulate - you might be able to use darktable’s really cool LCH tools for “chopping” out various wavelengths to somewhat emulate a low CRI light source.
But I think lowering the intensity for selected wavelengths would only be the “low CRI light source” half of the equation, as you still wouldn’t have access to information about what the varying surfaces wouldn’t have reflected if the wavelengths weren’t there to be reflected in the first place. But again, I’m just speculating, hopefully someone else has more concrete information.