“If Christ is within us at all times, He cannot then be received additionally during the Lord’s Supper.”
He certainly can. Jesus Christ is not limited by the heretical constraints of Jean Calvin.
If one has the indwelling Christ of what additional benefit is a 5 min digestion of a piece of bread to anyone? Either one has Christ or does not .
Does a piece of bread make one more holy? Know Christ better?
If the indwelling Spirit of God is not sufficient to live a holy life, to grow in the knowledge of Christ , to be led to do His will how is a 5min encounter going to change anything?