Looking into this further, I’ve determined that this jitter can be avoided if the Look At is placed before/above Rotate Around clip. It appears that the clips are evaluated in bottom-up order, and as long as Look At is evaluated after Rotate Around, there’s no jitter. So that’s good enough for me.
As an aside, I did later notice that Rotate Around has its own built-in Look At behavior associated with it, which would make sense to use. I use Rotate Around as an example, and in my own cutscenes I have more complex camera movement going on, which was also exhibiting this issue until I ensure that Look At was run after the camera movement.