The entire idea of accidence/essence seems to me to be medieval philosophical nonsense that misses the point. The sacrament of Communion is not in any way about the bread or the wine - those themselves are symbols, but spiritually, when a Christian ingests these symbols, they are covenental signs symbolizing that we are actually "ingesting" Christ himself. We are (spiritually) ingesting Christ's body and blood - as commanded in 1Co. 11 and Jo. 6 - but the bread and wine never changed physically. They are physical stand-ins communicating a spiritual reality.
These are just my own musings, and should not be construed to reflect any particular group.
Yes, they do communicate a spiritual reality. Just as all the sacraments, the Eucharist uses outward signs to communicate a spiritual reality - such as in Baptism, we see the sign of water washing a person, which visually shows what is happening to their soul as a result of God's Grace. However, the Eucharist is ALSO an actuality. He is visibly present, as He promised in John 6 and further explains and gives of Himself at the Last Supper. According to the "spiritual only" concept, the New Covenant no longer has the meaning that the Letter to the Hebrews mentions. "The Law was a shadow of things to come" - to bring about another shadow?" Jesus didn't come to give us more shadows, but Himself, His ENTIRE self. He continues to give of Himself in the Eucharist. This is the interpretation of the Church from the very beginning. Can you point to any Church interpretation that believed that Christ was NOT present in the Eucharistic elements?
St. Aquinas' "transubstantiation" is an Aristotlean term trying to explain what happens to the elements at time of consecration. It does not fully explain the mystery of the Eucharist, nor can anyone. But it is in line with the Church's teaching that the bread and wine are no longer "bread" and "wine" in the ordinary sense. Just as when Christ, at the Last Supper, gave them bread, and said "this is My Body". He didn't say, "this symbolizes My Body", or "this is like my Body". "This particular piece of bread is right now My Body" - is how the Church taught and understood Christ's Words.
Regards