Some of the worst crimes Fred Calvert committed against this film were done on "twos." Richard animated most of this film on ones, and Calvert cheaped out, creating shots intended to be done on ones, on twos.
For my rough cut, I was able to make a Calvert shot of the war machine on fire, which was done on threes and looked terrible, look good, merely by superimposing two other versions of the shot over itself at 1/3 opacity, one and two frames forward respectively.
Meaning: each frame, instead of being on threes, gradually dissolves into the next one. Since this is a fire effect which should look smooth, it suddenly was on "ones" and looked great.
But that's just an effect shot, a static shot. It wouldn't be possible to fake inbetweens on real animated shots.
But ...
For the rough cut, I tried it anyway, superimposing the shot over itself, 50% opacity, one frame forward .... to make "twos" dissolve into each other.
It looked awful.
For the final cut, I tried something different. Instead of putting it over itself at 50% opacity ... I thought, what if it was just at 12% opacity? Or some low number like that?
Just a shadow of another frame, just subliminally there.
I've tried it, and it does look better. It's subtle enough that it doesn't draw attention to itself and look cruddy, but the brain does see the action as looking smoother. This takes some of the "edge" off the worst Calvert shots.
It's kind of a dumb trick, but I'm gonna keep doing it. I think it works. We'll see.