Since I do quite a lot of 360ºx180º photography, let me share this: the focal length used on the camera, in practical photography, will result only in a different resolution, given the same camera. It is simple impossible to go wider than 360ºx180º. The wider the lens, the less resolution one get in real life, but also the simpler the capture session will be.
In Cinema 4d, the resolution is independent, and so the same lens setting can produce a higher resolution, hence more detail. Lenses are just magnification instruments. Longer lenses are just magnifying more. If you don’t move your camera’s position, every lens (besides, e.g., lens distortion) will have the same perspective even, just a different field of view. In this way, a longer lens needs more shots to be stitched and a wider less.
With the CV-VR cam you have a rig of six square 90º field of view cameras, which create a six sided view, a whole cubic representation of the world. This can be rendered out as such, like a un-folded cube, or calculated in an equirectangular.
If you increase the field of view ( a wider lens) you will get overlapping, and if those six result would be stitched together, the overlapping would be the parts that REDUCES the resolution of the final result. Nothing else would happen.
I hope I was able to bring this point home, nothing is wider than a 360ºx180º view. After that, anything repeats or overlaps. No gain at all.
If you need a wider view in the head set, that is not dependent on any render settings or camera settings inside of Cinema 4D. This is typically set by the HMD (head mounted display, and other presentation mode, might be in the metadata of the content and needs to be set, if no screen adjustment is possible.
Check out the link below, for nearly 200 tutorials about all of that. I shot for 3D since over two decades and as an artist with many exhibitions even longer.
Let me know if there is anything else, I’m happy to look into it.