Ok, let's extrapolate that...
Lets start with the light spectrum...
Well, you can do a great job of isolating a set of colors through selection of LED cores and phosphorus mixtures... And when you look at the spectrums of flashlights that offer cold and warm white colors, a lot of that is already covered.
I can see a combination of "generic" LED/COB powered flashlights and a few specialty devices with specific colors being a very effective application.
It will be tedious to point certain spectrums at certain parts of the plant, but for someone with a compulsion to finely control the lighting it could be really flexible.
It comes down to lumens and area distribution.
Maybe by the time I can grow again that might be a thing....