What I mean by that is, if Kenai is on one end of a level, and Koda on another, swapping bears moves the camera which pans across to meet the other bear. While the camera is panning, you can move immediately. And if you move immediately and pass an actor that is off camera, that actor is unloaded until it IS on camera.
This means that the distance between bears can be used to help one bear skip an obstacle, such as an elephant spraying water. (It's also worth noting that the water hitbox is only the fat end of it, not the shaft.
In Ice Cave 1 - Phase 2, Moving Koda to the elephant with Kenai at the beginning allows you to swap bears twice to pass the elephant, without needing Kenai to push the water spout. Likewise this can be done at the end of the level as well to get Kenai past the elephant faster.