That was already known, too. It does show that it doesn't create two completely equal, completely functional consciousnesses. But the problem with brain damage is people tend to also lose the ability to recognize that an ability is missing, so we can't just ask peóle "are you a little less conscious than you were before we took out that part of your brain?"

I agree. The best that can be said is something about communication of information between different parts of the brain. But my reason is more fundamental: we don't understand what consciousness is yet. Hence we can't know what questions about 'it' are meaningful let alone what conclusions to draw.

I can't prove you don't have two consciousnesses either, or maybe we all do and just don't notice.

You can't even prove GP has one!