I see there are two meanings to the words “metaphysical” and “mystical.” One set of meanings is what we, um, metaphysicians jokingly describe as “oogedy-boogedy.”
The other is boring to many. It might deal with questions like,
“Whether (and if so, how) we can say that God exists, triangles exist, my big toe exists?”
“Is there a difference between what a thing IS and what it is made of; are a beanbag chair and a golden throne both chairs?”
“Can we know the answers to these questions? How?”
When I read a clause like “What He [Christ] materially was,” the words “materially was,” get my attention. In my thinking what Christ IS is a such a different question from what he is made of that I want to stop there and look at “materially was” for a while.
So I think I'm right that we can't get far with Transubstantiation or the rest of that clump of questions.
As I have suggested, before we discuss what the Consecrated Bread is, I need to get clear about what regular everyday bread is.
You can debate semantics (and you might like to read what one of your monks says in regards to transubstantiation: https://www.praytellblog.com/index.php/2010/05/30/transubstantiation-and-aristotle-warning-heavy-philosophy) but whatever terminology you want to use, the only incarnated Christ whose body was "broken" and His sinless blood poured out was not that of an inanimate object whose appearance did not conform to what He manifested Himself to be as a partaker of flesh and blood, but one that was tangibly incarnated, and felt, behaved etc, as such and thus was "in all points tempted like as we are, yet without sin," (Hebrews 4:15) which stood in contrast to a christ whose appearance did not conform to what He manifested Himself to be "as concerning the flesh."
This is the Christ John identifies as Christ "come in the flesh" (1 John 4:2) versus one whose physical looks do not correspond to what He physically is. Certainly Jesus could feel our pain somehow without being incarnated, but the He chose to be so, and Scripture emphasize this, and even in His glorified physical body it was one of flesh and bones and in which He manifested His wounds and eat with the disciples, and thus His physicality identifies the true Christ.
That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of the Word of life; (For the life was manifested.. (1 John 1:1-2)
This is he that came by water and blood, even Jesus Christ; not by water only, but by water and blood. And it is the Spirit that beareth witness, because the Spirit is truth. (1 John 5:6)
Forasmuch then as the children are partakers of flesh and blood, he also himself likewise took part of the same; that through death he might destroy him that had the power of death, that is, the devil; (Hebrews 2:14)
For verily he took not on him the nature of angels; but he took on him the seed of Abraham. (Hebrews 2:16)
Though he were a Son, yet learned he obedience by the things which he suffered; And being made perfect [experientially], he became the author of eternal salvation unto all them that obey him; (Hebrews 5:8-9)
For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as we are, yet without sin. (Hebrews 4:15)
Behold my hands and my feet, that it is I myself: handle me, and see; for a spirit hath not flesh and bones, as ye see me have. (Luke 24:39)
Then saith he to Thomas, Reach hither thy finger, and behold my hands; and reach hither thy hand, and thrust it into my side: and be not faithless, but believing. (John 20:27)
If is only because Catholic priests cannot product the bloody physical flesh of Christ (alleged rare miracles notwithstanding) which a literal understanding if "this is my body which is broken for you" would mean that your theologian have has to labor to explain how Catholics receive the whole of Christ, the “true Body of Christ and his true Blood,” "the true and proper and lifegiving flesh and blood of Jesus Christ our Lord,” "the very body which he gave up for us on the cross, the very blood which he "poured out for many for the forgiveness of sins,"(CCC 1365) with His human body and human soul, with His bodily organs and limbs and with His human mind, will and feelings. "being corporeally present whole and entire in His physical "reality.” "Consequently, eating and drinking are to be understood of the actual partaking of Christ in person, hence literally.” (Catholic Encyclopedia>The Real Presence of Christ in the Eucharist) But which appear, behaves, tastes, etc., tests as mere bread and wine, yet which do not exist although as the true body and blood of Christ would, they do behave, taste, etc. and test as being what they appear to be, and when they do appear to be so in a negative way (decay) - and only if this can be seen - then the true Body of Christ and his true Blood no longer exist either under that misleading form.