Thank you for sharing these insights. Working with the camera is on my list, and having these postings would certainly save me a great deal of time, since I am hoping to use the new library.
In this article about the Universidad de la República updates of their scanner, they listed an interesting plug-in for creating surface plots from an image for 3D visualization. I have not used any of it, but a similar graphical representation would be a great way to illustrate the alsc issue.
PS. here is a quick comparison of the images above from @cpixip which enhances the visualization of the alsc unintended consequences for film scanning.
This is an excellent tool to visualize and evaluate the flatness of the scanner components chain (light+lens+camera).