No, it is not very narrowly determined, it takes some thought to find the Church sui iuris that most closely is the proper patrimony.
“Proper” - by whose definition? Folks who wouldn’t know one iconic style from another or be able (or willing) to fully appreciate both the commonalities and differences among the Churches, even those of the same Tradition or Rite.
The faithful can always apply for ascription to anoher Church sui iuris, I am sure that with good reason it would be granted.
“apply” presupposes that one coming from Orthodoxy, whose desire is to be ascribed to a Church other than the one to which he’d be ascribed by cookie cutter mentality, must formally apply. As I’ve already said, such is not the case. “good reason” is his or her desire and does not necessitate ‘applying’.
And the canons do not prevent “the individual any opportunity to participate in the spiritual life of the parallel Church” as you posted.
Let me try different phrasing. A strict interpretation would ascribe an individual to the parallel Church, whether it has a presence in the place or not. For example, if I were Bulgarian Orthodox, embraced Catholicism, and was ascribed to the Bulgarian Byzantine Catholic Church, I would be effectively ascribed to a Church which has had no US presence for decades. I might make that choice, regardless; however, I might instead elect to be ascribed to another Church of Byzantine Rite and Slav Tradition, so as to be subject canonically and spiritually, to an Eastern hierarch.
Why? Because I may not wish to be …
placed in the care of the Latin Church by default,
Why should I? Would I be encouraged to do so by the example of the pastoral attention lavished on the spiritual needs of such Catholics currently in Latin care? Hardly.
Look at the situation of Ethiopian and Eritrean Ge’ez Catholics. There are almost 2 dozen such communities in the US, the latter being most numerous. Only about a quarter of them are pastorally served by presbyters of their Church. In the remainder, their pastoral care is shunted off to the Latin ministries of other African communities - Zambian, Ugandan, etc - or to African-American/Black Catholic parishes - folks with whom they share no common religious praxis… Somehow, that wouldn’t make me get in line to be subject to the Latins.
or when another eastern jurisdiction exists in the place, another eastern Church sui iuris may have been made the proper jurisdiction by the Holy See.
For example, the Russian Greek Catholic ascribed faithful in the USA are in the care of the Latin Church ordinary.
The sentence immediately above seems to be a non sequitor to the one preceding. However, … Rome did (a century ago) designate the Byzantine Ruthenian Church as responsible for spiritual care of Croat, Hungarian, and Slovak Byzantines in the US and, similarly, the Ukrainian Greek-Catholic Church as responsible for Hungarian, Ruthenian, Slovak, and Romanian Byzantines in Canada.
It hasn’t, however, done much in that line anywhere of late (or in the interim), although it has, appropriately, done the obverse in a couple instances: Slovak Byzantines in Canada were provided their own Eparchy, eventually separated from the Ukrainian Metropolia, and given care of the Ruthenians; and, most recently, Romanian Byzantines in Canada were separated from the Ukrainians and jurisdiction of the Romanian Eparchy in the US was extended to Canada.
Notably, all other instances, in which another Eastern Church has extended its omophorion or jurisdiction to the unserved faithful of an ‘orphan’ Church, have been initiated by Eastern Churches, not Rome.
Thus, paper ascription of Russian Greek-Catholics to Latin jurisdictions notwithstanding, we have the Melkites, harkening back to their historic ties with the first Russian Greek-Catholic priest, Father Nicolas Tolstoy,
- St Andrew’s Russian (El Segundo CA) is formally under the spiritual omophorion of the Melkite Eparch and pastored by a priest of the Eparchy;
- Our Lady of Fatima Russian (San Francisco) is informally under the spiritual omophorion of the Melkite Eparch and at least one of its priests has his faculties from the Eparchy;
- St Michael’s Russian (NYC) is administered by a priest of the Melkite Eparchy;
- Our Lady of Kazan (Boston), prior to suppression, was under the spiritual omophorion of the then Melkite Exarch;
- the Russian parish in Australia is formally under the spiritual omophorion of the Melkite Eparch and pastored by a priest of the Eparchy, and,
- the Russian parish in Brazil is under the spiritual omophorion of the Melkite Eparch and presently administered by a priest of the Eparchy.
Ss Cyril & Methodius Russian (Denver) is formally under the spiritual omophorion of the Romanian Eparch. And, a Melkite priest provided pastoral care to several small, isolated Russian Greek Catholic communities in Siberia for several years, prior to being killed.
Likewise, as you point out
“Italo-Greek Catholics in the state of Nevada are canonically part of the (Byzantine Ruthenian) Eparchy of the Holy Protection of Mary (of) Phoenix …”
And, the Melkite Eparchy in Australia affords pastoral care to the Italo-Greek community there.
And, while there are indeed
“… Ordinariates for the faithful of various eastern Catholic churches without their own hierarchy in a few countries.”
]
they are, without exception, paper entities that cannot be said to do much of anything for the (mercifully) relatively few parishes subject to them.
Not sure there is much more to say. You’re pretty entrenched in your mindset and I’m getting tired of repeating myself, because you don’t want to acknowledge that everything is not as cut, dried, and pigeon-holed as some might like.
