Would "ever efficacious" do? That the sacrifice does not have to be represented in order to make it cover, or to be a propitiation for the current sins of the people, means that the ONE sacrifice of Christ IN time, on THAT very cross at Calvary, for ALL time was sufficient to render the sins of ALL time PAID IN FULL for those who receive it by faith.
Amen...We don't eat the body of Christ...We have faith that Jesus is the Christ and that he became the one time sacrifice for all, for all time...Faith... not hope, but conviction...
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.