Actually the correct answer was yes, and I accept your concession.
>What a lovely non-answer. Just as I thought. I can admit when I'm wrong; I can tell you specifically what would convince me. You have not, cannot, and will not.
I accept this concession too
>Does not the ark of the covenant pre-figure Mary carrying Jesus?
>Does not the flood pre-figure Baptism?
What is the pre-figure here? Did Jesus' words have a meaning which could have possibly been understood by the listeners? Was the meaning that they will live forever if they come lob off his arm and start dining on it?
>Every other time Jesus speaks in metaphors and he is asked to explain himself, Jesus does so. EXCEPT in John 6.
That's not true, and Jesus dod explain Himself clearly in John 6, specifically in all the verses you conveniently left out. The background for this passage is given before the dialog begins. This crowd is the 5,000 who were fed with 5 loaves and 2 fish. The Lord begins by saying "Truly, truly, I say to you, you seek Me, not because you saw signs, but because you ate of the loaves and were filled. Do not work for the food which perishes, but for the food which endures to eternal life, which the Son of Man will give to you, for on Him the Father, God, set His seal.” This is where eating is introduced in the narrative, and why. It is a metaphor introduced because of the context of the crowd's desire for food, with the intent of redirecting them toward Himself. The purpose is to remove food from the center and put Jesus there instead. "Therefore they said to Him, 'What should we do, so that we may work the works of God?' Jesus answered and said to them, 'This is the work of God, that you believe in Him whom He has sent.'"
Now they object that in order to receive the food which does not perish they must believe (not eat) in Him. So they said to Him, “What then do You do for a sign so that we may see, and believe You? What work do You perform? Our fathers ate the manna in the wilderness; as it is written, ‘He gave them bread from heaven to eat.’” They have proven their mind is still on their bellies, to believe in Him they demand a sign that feeds them, even though they just received a sign that fed them. They don't care about Him, their only gods are their bellies. Jesus responds to this insolence by reaffirming His significance, "Truly, truly, I say to you, Moses has not given you the bread from heaven, but My Father gives you the true bread from heaven. For the bread of God is that which comes down from heaven and gives life to the world.” Now this sounds really good to them, so they say "Lord, always give us this bread.” But the Lord Jesus does not satisfy their desire for something to chew on, because His purpose is to put Himself in the center of faith "I am the bread of life. He who comes to Me will never hunger, and he who believes in Me will never thirst. But I said to you that you have seen Me, and yet do not believe. All that the Father gives Me will come to Me, and the one who comes to Me I will never cast out. For I have come down from heaven, not to do My own will, but the will of Him who sent Me. Now this is the will of Him who sent Me, that of all that He has given Me I lose nothing, but raise it up on the last day. For this is the will of My Father, that everyone who sees the Son and believes in Him will have eternal life, and I Myself will raise him up on the last day.”
Isn't that a strange discordant shift if His purpose is to talk about eating Him physically? No, it's all consistent, and He has clearly defined what it means to eat Him here: to believe in Him. But the Jews are not eating Him because they do not believe in Him. They start grumbling after He defines the Bread of Life as Himself, because they are not believing. Jesus silences their grumbling by further answering why they don't believe in Him and further emphasizing the value of union with Him, "Stop grumbling among yourselves. No one can come to Me unless the Father who sent Me draws him; and I will raise him up on the last day. It is written in the prophets, ‘And they shall all be taught by God.’ Everyone who has heard and learned from the Father comes to Me. Not that anyone has seen the Father, except the One who is from God; He has seen the Father. Truly, truly, I say to you, he who believes has eternal life. I am the bread of life. Your fathers ate the manna in the wilderness, and they died. This is the bread which comes down from heaven, so that one may eat of it and not die. I am the living bread that came down from heaven; if anyone eats of this bread, he will live forever; and the bread which I will give for the life of the world is My flesh.” That is why they were not believing, because they had not been drawn by the Father to the Son. That's the point of the whole passage, everyone who believes in the Son has eternal life, but nobody will believe in Him unless the Father who sent Him draws them. At the end, when the Jews are turning away, He says "Does this cause you to stumble? What then if you see the Son of Man ascending to where He was before? The Spirit is the One who gives life; the flesh profits nothing; the words that I have spoken to you are spirit and are life. But there are some of you who do not believe.” For Jesus knew from the beginning who they were who did not believe, and who it was that would betray Him. And He was saying, “For this reason I have said to you, that no one can come to Me unless it has been granted him from the Father.”
Again, it's about who He is and being united to Him. The flesh profits nothing, His words are spirit and they are life. This had absolutely nothing to do with eating flesh, He Himself said it.
>Jesus even uses a different verb in Greek, meaning something closer to "feast" to drive home the point.
No the word simply means "eat" which is why all translations render it that way.
>t“I am the door” and “I am the vine” make sense as metaphors because Christ is like a door—we go to heaven through him—and he is also like a vine—we get our spiritual sap through him
The reason we know these are metaphorical is not because it seems fitting to you, it's because Jesus is telling a parable and identifying the characters, that is the sole meaning of the verb of being in these statements, it identifies the metaphorical character with its antitype. So in the parable of the sheepfold, Jesus is the good shepherd and Jesus is the door, not that He is literally a shepherd walking around with sheep or literally a door made out of wood nailed together but that these characters in the story represent Him. Take a look for example at when He explains the parable of the wheat and the tares, He identifies the characters by saying this is that eg "the field is the world". In the Bread of Life dialog Jesus is identifying Himself with the character of bread which falls out of heaven and gives eternal life to all who eat it. This is what it means when He says "I am the bread of life", He is no more a wheat product than He is a wooden door.