frank678 said:
If you are considering scene by scene maybe you should still render a version with these settings as back up. Is there a way to split your source file at the reel changes and render the reels individually with the settings to split the rendering time?

The problem isn't render time, necessarily. I did just render the entire thing, the only problem was that I was derpy and forgot to disable a single reference image overlaid on the video, so now I've got a still image halfway through the film that hangs on screen for a few seconds. Next weekend I may render it correctly.