I see the eating as figurative in this discourse, so I color Peter’s understanding as figurative, as you color it literal.
There is a figurative eating and a literal eating. Neither can be rejected. Jesus’ “Word of bread/life” instructed us to “take and eat” what is now His flesh and blood.
You keep wanting to separate the two, when Jesus did the opposite!
“What God has joined together, let no man divide”
Jesus was the bread who delivered God’s life giving Word to us. To remain in Him while he was “on the earth” meant following Him and witnessing His work, hearing His Teaching, and taking His council. But after He left, He established Himself (or gave Himself) to the 12 in the Communion of His Eucharist.
So henceforth, all who would “remain in Him” and “have a part in Him” and “come to Him” and “hear His Word”, etc… would need to do so through “eating” at the table of the Lord’s Supper, aka Mass.
You see, many Churches profess to commune of Him, but not one professes to contain the full deposit of faith. Where His body and blood are, so too is His deposit of faith accessible.
It is this principle that His life was extended to church communities who are in a true, yet imperfect, communion with the One Catholic Church. They have the Written Word, which without the Church of His Eucharist would not have been able to receive. The Written Word was celebrated and established within the table of His Eucharist. Technically, there is said to be two tables, the Written Word and His Eucharist.
The Church, in the CCC, professes the devotion and veneration of both eaqually.
What I find interesting about His Eucharist, is that it cannot be interpreted, or twisted, or picked and chose from. It is simply Him. Yet belief in Him being who He said he is and what He did for us, is inevitable for the person who regards the Bread as no longer ordinary, but supernaturally Him with us in completeness, yet unassuming and hidden. Just as He was while speaking in that synagogue, yet very much the divine Son of God!