I also hold that the accidents are elevated by their contact with the Divine substance.  Our Lord's Flesh was elevated by union with His Divine Person.  Similarly, when Our Lord rose from the dead and during His Transfiguration, the properties and attributes of His Body, which remained the same, were elevated and "glorified" ... and yet it was the very same Flesh.  He did not somehow take on a different glorified Body, but the very same Body was glorified, taking on different properties, being elevated to a different state.  Similarly, when the accidents of the bread are united with the Divine Substance, they are elevated to a different level, while remaining essentially the same.  To me, holding otherwise, that the accidents remain on their same crass level as before Transubstantiation is a step in the direction of the Protestant notion of consubstantiation.

Just on an anecdotal level, when I was a Novus Ordo altar boy, I would occasionally bring home some unconsecrated hosts from the sacristy and would eat them, sometimes playing Mass with my younger siblings.  I would say they they didn't even taste quite the same as what I now experience during Holy Communion.  When one receives Holy Communion with the same hosts when consecrated, even the way the senses perceive the Blessed Sacrament seem "different" and elevated vs. mere consumption of the same un-consecrated host ... and it's not merely due to a different psychology in approaching the Blessed Sacrament.  There's something different about the entire experience, including the reaction of the senses to the elevated or glorified accidents of the Blessed Sacrament.  So there's a practice in the Eastern Rite where the faithful would go up after Divine Liturgy to receive some of the left-over (unconsecrated) altar bread.  In the Eastern Rite, they have to cut and prepare the loaves of bread, so that remnants remain outside of what's used for the Transubstantiation.  I hold that the sensation of taste is different between the two, different between receiving the consecrated bread and then consuming the unconsecrated bread from the same loaves.  Take that for what it's worth, but I am convinced that they "taste" different apart from any psychological phenomena one might try to attribute it to.  When receiving the same bread, Transubstantiated, the taste seems more sublime, elevated, less crass, beyond any differences that might be attributed to mere psychological forces.  But take that for what it's worth.

So, even though the accidents remain essentially the same, I hold that they are elevated, transformed, and glorified by their contact with the Divine Substance.  There's nothing incompatible with the accidents remaining essentially the same while being elevated, purified, and in a sense glorified by their being united by the Divine Substance, just as Our Lord's glorified and transfigured Body remained essentially the same Body He had during His entire life.  As the saying goes, grace elevates nature (without thereby destroying it).

Just on an anecdotal level, when I was a Novus Ordo altar boy, I would occasionally bring home some unconsecrated hosts from the sacristy and would eat them, sometimes playing Mass with my younger siblings. 

My son asked me if I could order some unconsecrated hosts, for him to snack on.  I told him NO, it is not good to get that familiar with something that is supposed to be set aside for confecting the Holy Eucharist.  I wouldn't go so far as to say it is sinful, but something about it just doesn't seem quite proper.

But then there is the Polish oplatki, shared with family members at Christmas time.  It is essentially the same composition and texture as the host, just cut in square sheets and impressed with devotional images.  You break it off into pieces and family members share it as a sign of devotion and unity, similar to the Orthodox antidoron.

I'm Polish and I have never heard of this whatsoever. I had to Google it and I was shocked because this sounds suspiciously similar to what is done with the matzah at a passover seder.  Perhaps it's a regional custom within Poland as I'm certain if it was something my very Old World Catholic grandparents were familiar with they would have passed down to my dad and us grandkids.  You learn something new every day!

Oh, yes, it's very common, at least amongst any Poles I've ever known (including my wife and son's family):

https://en.wikipedia.org/wiki/Christmas_wafer

My son asked me if I could order some unconsecrated hosts, for him to snack on.  I told him NO, it is not good to get that familiar with something that is supposed to be set aside for confecting the Holy Eucharist.  I wouldn't go so far as to say it is sinful, but something about it just doesn't seem quite proper.

But then there is the Polish oplatki, shared with family members at Christmas time.  It is essentially the same composition and texture as the host, just cut in square sheets and impressed with devotional images.  You break it off into pieces and family members share it as a sign of devotion and unity, similar to the Orthodox antidoron.

I haven't seen host scraps in US stores. Not uncommon in Italy, Spain or Latinamerica. "Obleas" are snacks made with the same basic ingredients and you do find them in the US in latino stores in the candy section. See pics.

I haven't seen host scraps in US stores. Not uncommon in Italy, Spain or Latinamerica. "Obleas" are snacks made with the same basic ingredients and you do find them in the US in latino stores in the candy section. See pics.

a. The last cloistered Carmelites in NYC, before they left town, used to sell packets of altar bread scraps in their gift shop. 

b. A variety of soft nougat called torrone is wrapped in an edible outer layer called ostia, see photo below. These were among the sweets that many convents (besides Carmelites) once produced to support themselves in the past.

But does the starch remain "wheat"?

Even with conventional hosts, the wheat bran has been removed, as is the case with all white flour.  So removing part of the wheat grain doesn't seem as though it would jeopardize validity. 

This would be a good question for Aquinas.

The issue is not whether "wheat starch" is "wheat." The issue is whether something made from almost pure wheat starch can be "confected into bread" and has "the nature of bread."

White flour existed in the Roman Empire during Roman times. Removing the bran and the germ are not difficult. Separating the gluten from the starch to a level of .001% gluten is difficult.

In order to make "bread," as has been said above, a certain percentage of gluten is needed. Definitely, the flour should have well over 1% gluten for the resulting substance to be called "bread."

Nonsense.  There’s nothing contrary to Trent in considering that God would prevent the accidents from behaving in such a way as to not do harm.  In Eucharistic miracles, God changes the accidents entirely.  God can do whatever He wants.  Some saints were protected by God from being affected by poisons.

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You can't just posit that God would work a miracle in some particular circuмstance. God decides if He wants to work a miracle, and they are very rare events and cannot be predicted by man.

This question was discussed by pre-Vatican 2 theologians and none of them said what you are saying, that a gluten-allergic person would be preserved by a miracle. On the contrary, they came up with solutions so that the person could receive communion without getting sick.

I'm not aware of any basis of your idea in traditional theology.

I was just informed there is a SSPX priest who uses a gluten-free host for his own communion. I was told this by a former sacristan.

I'm assuming that his gluten sensitivity became known after ordination.  I have to think that under traditional rules, someone with a known gluten (or alcohol) sensitivity would have been irregular for ordination, in that he couldn't confect the Sacrifice without significant accommodation, and even then, he has to purify vessels and consume the contents, which would have gluten (albeit very small traces) in them.

It's probably not an issue in Newchurch, as they'll ordain anyone they can get through the seminary... unless, of course, he has a strong preference for the TLM or questions anything about Vatican II or the 60 years of its implementation.