Simulating FOV changes in VR for Google-Cardboard with Unity

Question

I am working on my first VR project, in which I am displaying satellite data inside of a sphere. The camera/observer is placed in the middle of the sphere and "looks up" at the satellite data, which is rendered in all directions. I am doing this under Unity 2021 using the latest Cardboard SDK and running it on a Pixel-3 on Android 12. After some tinkering, I managed to get the scene to render, but the observer is MUCH too close to the scene. I am aware that the FOV is fixed by the device, but is seems to me that I should be able to scale the scene to "zoom out". However, nothing I have tried works, including the following;

1. Simply changing the size of the sphere (which is just a single "flip-normalled" object)
2. Changing the camera parameters (Note: I now understand that these have zero effect in VR, as the device sets the FOV).
3. Placing the camera object, embedded in an XRRig prefab in my case, inside an arbitrary "GameObject" and re-scaling the object (as specified here)
4. As in 3, but placing every object inside the GameObject

None of these have any effect on the eventual scene as built on the device. I am at a loss. Surely what I am attempting is possible? I really just want a tiny observer, i.e. to make the "sky" seem much farther away. Any/all help appreciated.

Cheers.