Gray used ECL to broaden “subject to the jurisdiction” to include domiciled aliens.
He wasn't running for President. If he had been, they clearly would have declared him eligible, because they clearly found him to be a natural born citizen.
WKA held that a child born in the United States to domiciled alien parents was a Fourteenth Amendment “citizen of the United States.”
They also stated that the 14th Amendment affirmed the ancient rule of citizenship, and that this same rule applied in England, in the Colonies, and in the United States. By that rule, children born the country were natural born citizens/ subjects, unless the children of diplomats or invading armies.
It's really not complicated. And every legal authority that matters agrees that this is what they found.
Even the dissent in the case recognized that the ruling said children born here of resident aliens were eligible to be President.