Sec. 3. And be it further enacted, That the children of persons duly naturalized, dwelling within the United States, and being under the age of twenty-one years, at the time of such naturalization; and the children of citizens of the United States, born out of the limits and jurisdiction of the United States, shall be considered as citizens of the United States: Provided, That the right of citizenship shall not descend to persons, whose fathers have never been resident in the United States: Provided also, That no person heretofore proscribed by any state, or who has been legally convicted of having joined the army of Great Britain, during the late war, shall be admitted a citizen as aforesaid, without the consent of the legislature of the state, in which such person was proscribed.
It's late. Do you interpret this to mean that the heir to the throne is or is not eligible to be President as described in my hypothetical?
What you have cited is specifically a "naturalization" act of Congress and thus has no authority to lessen a Constitutional restriction.