After switching back and fourth and really looking closely at each one I ended up deciding that I liked the bottom right photo, even though I could recognize the top right one had a more classic film look. For me it was just because there was more detail in the colors. The original scan was kind of washed out in the blues I guess, as well as being a little more red in the dirt area.
Maybe this is prejudiced because this is how I remember old photos to be... But then, isn't that the point of scanning old negatives anyway - to recreate what the old images on them would have looked like at the time?
Arguably though, the correct solution is to preserve the source information as much as possible, so similar to what it proposed - scan the images using light sources that correspond to the peaks of the chemicals used in the negative, and then colour grade directly from that using a modified inverted curve.
Doing it that way should permit both outputs by changing the curves used in colour grading, and I suspect the real issue is just "inverting colours" isn't the most appealing visually, just as most professional photos are colour graded to some extent because the raw images don't look as appealing.
Maybe the bottom one is a more realistic reproduction of the scene, but I also prefer the top one, which is more saturated and closer to what I associate as a film image.
Each kind of film has its own character and color variations; it’s silly to try to neutralize everything.