Natural Born is a specific term that cannot be changed by State law or even Federal Statute. It must be interpreted by Federal Court under Federal question jurisdiction.
I don't disagree with that, and think the framework I outlined does that. At IV. Sec. 2 hasn't been repealed or amended, and it looks to state citizenship. For purposes of US NBC, the federal court could use either the 14th amendment, which is literally born in the US, or it could use Art IV, Sec. 2, which is citizen of a state.
The number of times an NBC issue can come up is once each 4 years, at most. I don't think a court should try to anticipate all the permutations of birth circumstance in advance, and for Cruz, the question is easy to resolve - Cruz was not a citizen of any state when he was born. A different fact pattern with kid born abroad while parents are on a one month vacation merits a more detailed and ranging view of evidence than an ordinary citizenship case, but it's only once each 4 years, so the general/simple rule works fine for all but presidents-elect.
I'm not advocating changing the term, just advocating introduction of domicile for purposes of determining the state citizenship of the child.