metanoeo has no resemblance to the meaning of the word 'penance.' It's literal translation means to 'change the mind, to reconsider - be convinced'. In context it's closest approximation in English is 'repent.'
The falling away of the Methodist church in England is sad, but it is a symptom of a greater dissolution in the West and in post-war Europe in particular, where an existential crisis has taken deep root in the form of post-modernism. The church in all her branches has not been exempt from this, either.
Even so, come quickly Lord.
In fact, I would insist that the Catholic translation reflects most accurately the meaning.
It is true, indeed, that “metanoiete” literally means “change your mind”. But so the “Spirit”, “Ruach” means “breath”, “Resurrection” means “stand up again”, etc. We translate meanings, not root components.
So what is the meaning of “metanoiete”? The immediate context in Luke leads up to the parable of the fruitless fig tree; the gardener pledges to apply work to it: dig around it and fertilize it. Next, the pharisees accuse Jesus of what? of working, on a Sabbath. So the immediate context points not to changing of the mind but of physical deeds.
Who said “metanoiete” first? St. John the Baptist. What example did he give? Ascetism: hair shirt, fasting, solitude, the classic forms of penance. Again, the meaning is that we should do something, not just think something.
Jesus Himself showed us not just thoughts but deeds: He fasted, went alone for forty days, climbed mountains to pray, and let His flesh be abused.
But one person, Judas, — he “repented”. Changed his mind.
So, no, Douay is the only translation to read if you read in English. Other translations have merits, especially Catholic ones, but accuracy is not one of them.