I think everyone agrees that Romans 9-11 is pretty bewildering. Here’s the part of Romans 9-11 that I find helpful for UR.
Romans 9-11 is a defense of God’s reputation (“Is God unjust?” Rom. 9.14; “Did God reject his people?” Rom. 11.1). How can God be trustworthy if God has dealt with the Jews, in the wake of their rejection of Jesus, so harshly? Was God just setting Israel up to take the fall when Jesus arrived? That seems cruel.
In response Paul deploys an array of (at times confusing) arguments. First, Israel (and humans generally) can’t really object to God’s actions. God can do what God wants to do (“But who are you, a human being, to talk back to God?” Rom. 9.20). Second, God has always worked with remnants in Israel (“only the remnant will be saved” Rom. 9.27; “there is a remnant chosen by grace” Rom. 11.5). Thus, we shouldn’t be shocked that only a minority of Jews accepted Jesus. Third, as grace comes to the Gentiles Israel will become “envious” and return to God (“salvation has come to the Gentiles to make Israel envious” Rom. 11.11).
But having walked through all these arguments Paul seems to sense that he’s not yet won the day. Objections still linger. So he winds up the argument with a “mystery” (Rom. 11.25). And the mystery is this: Yes, Israel has experienced a “hardening” (Rom. 11.25) to give the Gentiles a shot at salvation. Yes, as a part of God’s foreknowledge and plan Israel was made to be an “object of wrath prepared for destruction” (Rom. 9.22). Israel is now an “enemy” of God for the sake of the Gentiles (Rom. 11.28). However, Paul contends that this does not mean that God is going back on God’s promises. God’s promises are “irrevocable” (Rom. 11.29). Well, how does Paul reconcile this seeming contradiction? How can Israel be an enemy of God and an object of wrath prepared for destruction and still be saved? Paul really doesn’t have a logical answer. His answer is doxology (Rom. 11.33-36): “Oh, the depth of the riches of the wisdom and knowledge of God! How unsearchable his judgments, and his paths beyond tracing out!”
But what is clear is this: Those who were previously “enemies” of God and “objects of wrath” will be saved in the end. Right before the doxology Paul wraps up the entire argument with this:
The key theological point for UR is this: Being an enemy of God and an object of wrath predestined for destruction does not foreclose on salvation. Objects of wrath and enemies of God are saved in the end.
No wonder Paul ends in a song of praise.