So I just noticed that the TweenOrthoSize is broken. It's trying to alter the camera's fov, rather than its ortho size:
override protected void OnUpdate (float factor, bool isFinished)
{
//This is altering the wrong camera property
//cachedCamera.fov = from * (1f - factor) + to * factor;
//This is what it should be doing
cachedCamera.orthographicSize = from * (1f - factor) + to * factor;
}
I'm guessing this isn't one people use a lot since this hasn't been caught before, but just in case, I thought I'd throw it up here.