[sometime lurker]

This is taken out of context. The 1350 act referred to "enabled children of English nationals to inherit though born abroad." It is precursor to the 1700 act that declared them natural born subjects. Your quote says

The result of the principal case is to limit the category “natural born” to those who become citizens under the doctrine of jus soli;

and then goes on to expand the definition of natural born to extend to those born abroad to English citizens. Much like our 1790 Naturalization act did. It does not say that jus soli doesn't apply. ( and of course, it is about Britain, which you haven't wanted to see for material that contradicts your point...)

[DiogenesLamp]

This is taken out of context. The 1350 act referred to "enabled children of English nationals to inherit though born abroad." It is precursor to the 1700 act that declared them natural born subjects. Your quote says

Don't take it up with me, I didn't write it. Did you miss the references as to who did?
(8 1 Willoughby, The Constitution §202 (1922); Flournoy and Hudson, Nationality Laws (1929); Harvard Research in International Law on Nationality, 23 AM. J. INT. L., Spec. Supp. 80 (1929).

Whether it be correct or not, it is the opinion expressed by those legal scholars in 1929, and it asserts that jus Sanguinius was the dominant requirement of natural born citizen status.