If you want to get serious on this, get good quality color chart[1] and use that to compare different light sources etc. Just eyeballing resulting colors from random photos and guesstimating the various spectral curves gets you only so far.
Yes, but you'd want that colour chart on the type of film you're scanning, for reasons explained in the OP. Sadly all I found in a brief search were calibration targets on slide film, not negatives.
Back in the early 90s I used a Noritsu printer. We had reference negatives on all the different film stocks, or at least all the ones we regularly saw there. We would group the jobs by film type. Set the calibration by the calibration negative and judge exposure and basic color correction by direct viewing of the negative. Another person would check the prints and flag any that needed to be redone for color, dust, exposure, etc. Then we’d change film types.
The next time I touched a photofinishing machine in the early 2000s you looked at a screen to make adjustments and we offered digital services like scanning and printing from digital files. I still used my negative reading skills to talk to customers when we were troubleshooting results. Putting the negative on the light table to show them how thin they were or how wildly the color changed when you switched what kind of light the picture was shot in was the quickest way to resolve quality complaints.
I'd imagine that just grabbing the reflective target and shooting it yourself on film would get decent results? Assuming the target patches have good spectral coverage
[1] e.g. https://www.silverfast.com/products-overview-products-compan...