There are a lot more nuances than your analysis admits, and one is the assumed inflection of the speaker. Consider "Does anyone know Y?". Depending on how it

There are a lot more nuances than your analysis admits, and one is the assumed inflection of the speaker. Consider "Does anyone know Y?". Depending on how it is said, it could be either a straightforward question about whether anyone knows Y, or with an upward inflection on "anyone" it could mean "I doubt anyone knows Y, but it's possible someone does." With that same inflection on a person's name, "Does even Person know Y?" has the same meaning as your "Does even X not know Y?"