I doubt you can find a single Mormon or Orthodox or Moslem on Earth who would agree that his or her religious rights or obligations were or have been infringed or advanced by anything in Westphalia ~ yet, Catholics and Protestants, in general, will always point to this event that brought about the MODERN nation state as being of particular interest to Catholics and Protestants!
Westphalia drew, inadvertently, a big line between European Christians, and all others.
Wow,,,lol. America, the legacy of the “peace” of Westphalia! Because we were the “successor” state of Spain? Ok there Stretch Armstrong, we did not inherit their legalities.
The concept was to drive them and their backwards European legalities OUT of the new world. We were certinly not in the business of a continuation of their silliness.
And you seem to fixate on how popes and protestants all signed the treaty, but mormons, moslems and orthodox didnt. The people who signed the treaty were rupudiating the concept in 1640 Europe that power was properly dispensed through Monarchs who in some way hailed back to the pope. Why would islam of 1640 or Orthodoxy need to sign that? Their lands were not claimed (in the larger sense) by the papacy.
There was nothing for them to settle in that treaty. And the lands where they flourished, had nation states that were not conetested in the main by the pope or his euro-monarchs.
You are giving far too much downstream effect to that treaty. It did little more than codify what force of arms established. And though you say the pope agreed, “The Holy See was very displeased at the settlement, with Pope Innocent X in Zelo Domus Dei reportedly calling it “null, void, invalid, iniquitous, unjust, damnable, reprobate, inane, empty of meaning and effect for all time”.