I really like thinking about "ever-efficacious"! And I think it's a useful term, and what you say is good, if not quite perfect.
"Ever" still has a slight savor of "extent", doesn't it? My guess is that that is where we would find the problems.
But certainly the notion of reaching through all time and of being all-sufficient is indisputable.
This is sketchy and suggestive and not at all rigorous. I would say that in Rom 8:17 and good old Col 1:24 we find the merest hint that we can, should, even must somehow add to the infinite. Maybe "contribute" would be more better... :-) It is already infinite and infinitely sufficient. No prayers, Masses, penances, or any work of any kind whatsoever could augment it. I can't imagine any serious Catholic thinker disagreeing with that.
As the OP rightly says, we have a tendency to worship the works of our hands. And so, for many Catholics, Satan has appointed a demon to whisper in their ears something quite contrary to Ps 51: 16-17.
The therapy for that madness lies in the Beatitudes, and in the notion of poverty. Though we must not appear before the Lord empty-handed, yet all we have to bring is what he has already done. I would say that it's not the fault of the Masses that some reckon them up like Pokemon chips. But there's no question that some do and obscure discourse by doing so.
As for the words that we use to kinda, sorta try to vocalize what must be acknowledged, if we're honest, is too insufficient to ever come close to getting it "quite perfect", we can begin to understand the reasons why volumes of writings through the ages exist from men and women who dared to attempt to do so. Scripture tells us that, "He who sits in the heavens laughs; the Lord holds them in derision." (Psalm 2:4) those who imagine they can throw off His laws for the universe and His dominion over all, but, also, as Paul wrote in I Corinthians 2:4-5, "My message and my preaching were not in persuasive words of wisdom, but in demonstration of the Spirit and of power, so that your faith would not rest on the wisdom of men, but on the power of God."
I think it is in this area, the "wisdom of men", that we can get tripped up and in many areas we should learn to be submissive and obedient rather than imagine we must figure out the nitty-gritty of everything God-wise. It is, perhaps, for these very reasons why there is a disconnect between what Catholics have come to believe about the Eucharist and what many non-Catholic Christians do. Rather than condemn and bicker over our differences, we should try to be respectful and agree to disagree for the sake of peace and brotherly love. There are plenty of truths in the Christian faith that CAN be understood and our acceptance of them determines whether or not we can even BE saved.
My contention, all along on these threads, that delve into the topic of the Eucharist, has been to express this belief that in some things we will not be capable of a full and total understanding and to accept this and not allow our differences to boil over into insults and hatefulness. For this reason I thank you for your tone and efforts to respectfully discuss different opinions and retain what we all should try to - humility and being constrained by the love of Christ.