Ok, I tested it and in my opinion this continuous scale change will never work, because it just doesn't look very realistic. Actually this whole concept of two different perspectives in one scene is not very realistic, but I think it would work well if you took advantage of the big rock in the middle and switch to different perspective while the actor is completelly hidden. What I'm thinking of, technically, are two sets of scale levels, and switching from one to another when walking behind the rock. Of course, currently it's not possible to control scale levels at runtime, but I could add this functionality relatively easily.
So what do you think?