So how does that point automatically transfer over to meaning that the person who does receive the gifts and calling of God (because God never stopped calling people from among his group) can never ever lose his salvation?
Because not only has God not stopped calling people (Jews and Gentiles, individually), He has not stopped gifting those same individual people with eternal life. And eternal life is, well ... eternal. I.e. It is irrevocable. Just as His calling is irrevocable, so is His gift of eternal life. Both individually and corporately. Just ask the 7,000 and Paul. Any fair evaluation of letter Paul wrote to the Romans and specifically spoke to
Gentile Romans at the chapter 11 point can see the clarity of what Paul was saying.
The 'argument' that Romans 11 is about corporate/national calling and gifting and not also about individual calling/gifting is absurd given Paul's use of his individual self and the 7,000 individuals he used for examples. Clearly it's an attempt to avoid the obvious implication of eternal life being an irrevocable gift of God.
Just as absurd as if Romans 11 were only about calling/gifting to Jews, when Paul specifically says he's speaking to Gentiles. Not to mention that groups of people are made up of individual people, by definition.
Anyway, that was my point. Your statement: "The argument is that the gifts and calling of God are irrevocable
in regard to the nation of Israel, not in regard to any one individual person not being able to have them revoked once they accept the gifts and calling of God" doesn't stand up to credibility, IMO, given the quotes from Paul's context I posted. Repeated here for clarity:
Romans 11:1-2, 4-5 (LEB) Therefore I say, God has not rejected his people, has he? May it never be! For I also am an Israelite, from the descendants of Abraham, of the tribe of Benjamin. God has not rejected his people, whom he foreknew! Or do you not know, in the passage about Elijah, what the scripture says—how he appeals to God against Israel? ... But what does the divine response say to him? “I have left for myself seven thousand people who have not bent the knee to Baal.” So in this way also at the present time, there is a remnant selected by grace.
His point is clearly that in this present time, just as in Elijah's time, God calls and gifts individuals. 7,000 plus one plus more are
His people. Irrevocably so.