How can I control imp scale / distance while possessing a puppet in first person mode?

I have a puppet I'm possessing with camera distance 0, emulating a first-person view. I've also allowed the imp to be viewable during this possession. However, the imp is very close to the puppet view and I can't find a way to change the distance or scale of the imp. I know there is a tab for this under the camera's tweak menu, but when I change values there on the deluxe puppet's built-in camera, it doesn't seem to have any effect.