What you, I, or Cruz think is irrelevant if the courts do indeed inject themselves.
It's irrelevant to the outcome "as a matter of law," I agree with that.
If he's found eligible, some voters will reject the SCOTUS holding, and withhold voting for Cruz. He's damaged to some extent, no matter what.
And if he's ruled eligible, SCOTUS is going to have students of the law looking at the decision as a pivot point, like Wickard v. Filburn is a pivot point. A reversal of the rule stated in every case that came before.