@ednisley thank you for the post and welcome to the forums!
I’m intrigued by your audio idea. Do you have any experience with capturing optical audio tracks? At one point we had discussed capturing sound from the film with hardware. How hard of an electronics problem do you think that would be to solve?
If I understand your suggestion, it would mean we capture the audio as a digital file (in what format, I’m not sure) and then apply a time-mapped adjustment to that file based on the recorded variance of speed during the scan. Is that right?