[jackw01]

Author here, I was curious about this too since I would have expected most film scanners from the 90s-2000s to use incandescent light sources if high-CRI light was really the way to go. Minilabs that made direct optical prints to RA-4 paper did use white light sources with filters, since RA-4 paper is already only sensitive to narrow bands of light. In the mid-90s, Fujifilm and others introduced minilabs that could also scan film and produce prints from digital files. These all used RGB LEDs to scan the film, and they must have had a very good reason to since blue LEDs were barely ready for commercial use at the time.