Congress has the power — it’s their job, in fact — to fill in any gaps or vagueness in the language of the Constitution. The federal courts can then strike down laws where those definitions are inconsistent with or flatly contradict the Constitution itself.
It would certainly be within the power of Congress to define “natural born citizen” within those limits, as it did when it passed a joint resolution declaring John McCain to be one.
JSR's are worthless, they have no effect as law.