The problem is CC sphere is an efffect that has to render pixels out,
it takes whatever you input to it, converts that into pixels (even vector .ai, continously rasterized pre-comps or texts) and then wraps them around a sphere.
So if you come close to the sphere or increase the radius you’re inevitably going to bump into pixelation.
The workaround is to create a Huuuuge pre-comp of several thousand pixels wide containg your text-wireframe.
You apply a CC sphere with a large radius to that and scale the layer down, but even then, at some point you’ll see pixelation, and it will render very slowly.
perhaps it’s best to do something like this in a 3D app.
Or can you post a still of what it should look like before the pixelation becoms too severe ?