Disclaimer: I only read a few posts in this thread, so I apologize if I repeat what someone else may have posted. I am writing from a (there is no the) full preterist perspective. The view is my own and I don't represent or speak for any particular sect. A couple of details are still a bit fuzzy, but I'm hoping as I write my thoughts down here, they will become more crisp, which is what often happens.
In order to understand my view regarding Romans 11:11 and following, it is helpful if I point to the background in the OT that, to me, informs the discussion.
It is necessary, or at least, very helpful, I believe, to understand that Deuteronomy 32 is prophecy about the last days of the then (in Deuteronomy), newly ratified Sinai Covenant and the house of Judah's Temple based theocracy.
Moses says that his song is about their last days, when God would slay all but a small remnant of them:
[Deuteronomy 32:20-27 NASB20] (20) "Then He said, 'I will hide My face from them, I will see what their end [will be;] For they are a perverse generation, Sons in whom there is no faithfulness. (21) 'They have made Me jealous with [what] is not God; They have provoked Me to anger with their idols. So I will make them jealous with [those who are] not a people; I will provoke them to anger with a foolish nation, (22) For a fire has flared in My anger, And it burns to the lowest part of Sheol, And devours the earth with its yield, And sets on fire the foundations of the mountains. (23) 'I will add misfortunes to them; I will use up My arrows on them. (24) '[They will be] wasted by famine, and emaciated by plague And a bitter epidemic; And the teeth of beasts I will send against them, With the venom of crawling things of the dust. (25) 'Outside the sword will make [them] childless, And inside, terror-- Both young man and virgin, The nursing child with the man of gray hair. (26) 'I would have said, "I will wipe them out, I will remove the mention of their name from humanity," (27) Had I not feared the provocation by the enemy, That their adversaries would misjudge, That they would say, "Our hand is triumphant, And the LORD has not performed all this."'
This should all look familiar to you. Peter, in Acts, says that the Sign of Joel had arrived, providing proof positive that the Last Days (of the Judean Temple based Theocracy) had arrived:
[Acts 2:14-21 NASB20] (14) But Peter, taking his stand with the [other] eleven, raised his voice and declared to them: "Men of Judea and all you who live in Jerusalem, know this, and pay attention to my words. (15) "For these people are not drunk, as you assume, since it is [only] the third hour of the day; (16) but this is what has been spoken through the prophet Joel: (17) 'AND IT SHALL BE IN THE LAST DAYS,' God says, 'THAT I WILL POUR OUT MY SPIRIT ON ALL MANKIND; AND YOUR SONS AND YOUR DAUGHTERS WILL PROPHESY, AND YOUR YOUNG MEN WILL SEE VISIONS, AND YOUR OLD MEN WILL HAVE DREAMS; (18) AND EVEN ON MY MALE AND FEMALE SERVANTS I WILL POUR OUT MY SPIRIT IN THOSE DAYS, And they will prophesy. (19) 'AND I WILL DISPLAY WONDERS IN THE SKY ABOVE AND SIGNS ON THE EARTH BELOW, BLOOD, FIRE, AND VAPOR OF SMOKE. (20) 'THE SUN WILL BE TURNED INTO DARKNESS AND THE MOON INTO BLOOD, BEFORE THE GREAT AND GLORIOUS DAY OF THE LORD COMES. (21) 'AND IT SHALL BE [THAT] EVERYONE WHO CALLS ON THE NAME OF THE LORD WILL BE SAVED.'
He call HIS generation a "crooked generation" using the same word as Moses used in Deuteronomy 32:5!:
[Acts 2:40 RSV] (40) And he testified with many other words and exhorted them, saying, "Save yourselves from this crooked generation."
Deuteronomy 32:21ff is the very passage that Paul quotes in Romans 10:
[Romans 10:19 NKJV] (19) But I say, did Israel not know? First Moses says: "I will provoke you to jealousy by [those who are] not a nation, I will move you to anger by a foolish nation."
Deuteronomy 32:22-25 describes God's a fire, arrows, famine, plague and the teeth of beasts and more. These are described in Matthew 24, Luke 21 and the Beasts of war described in Revelation:
[Luke 21:20-23 NKJV] (20) "But when you see Jerusalem surrounded by armies, then know that its desolation is near. (21) "Then let those who are in Judea flee to the mountains, let those who are in the midst of her depart, and let not those who are in the country enter her. (22) "For these are the days of vengeance, that all things which are written may be fulfilled. (23) "But woe to those who are pregnant and to those who are nursing babies in those days! For there will be great distress in the land [of Judea] and wrath upon this [Judean] people.
For the reason that this is about the house of Judah, please see Hosea 1. Israel had become covenantally dead long before the first century. Ezekiel prophesied to the dead that God would cause them to be resurrected:
[Ezekiel 37:11-14 NLT] (11) Then he said to me, "Son of man, these bones represent the people of Israel. They are saying, 'We have become old, dry bones--all hope is gone. Our nation is finished.' (12) Therefore, prophesy to them and say, 'This is what the Sovereign LORD says: O my people, I will open your graves of exile and cause you to rise again. Then I will bring you back to the land of Israel. (13) When this happens, O my people, you will know that I am the LORD. (14) I will put my Spirit in you, and you will live again and return home to your own land. Then you will know that I, the LORD, have spoken, and I have done what I said. Yes, the LORD has spoken!'"
This was the earthly mission of Jesus:
[Matthew 4:19 NASB20] (19) And He said to them, "Follow Me, and I will make you fishers of people."
The were the wayward son of Luke 15 while the Judean were the older son!
I don't have time to draw together all the connections, but you get the idea. Paul (and the whole NT) is speaking of the Last Days, not of the whole planet, but of the house of Judah (which was the last of the Sinai Covenant People. About 40 years after the earthly ministry of Christ, the Temple, Jerusalem, etc. was all destroyed and there were no more biblical Judeans (which is the actual word translated "Jews" in the NT). The Sinai Covenant is over and only those Jews (and gentiles) that are fused with Christ in the New Covenant that are the Israel of God aka the Members of the Body of Christ, the Bride of Christ, the Branches of the True Vine, the Sheep of the Good Shepherd, the Living Stones of the Building Not Made With Hands, the City On a Hill, the New Jerusalem, God's Field and God's Building, etc., etc., etc.
So what Paul is speaking about in Romans 9-11 is that God's promise for the Deliverer to come to/from Zion and take away their sins was that when Jesus returned c. 70 AD/CE and emptied Hades and separated the sheep from the goats and so on, he was not talking about gathering the Lost Sheep of the House of Israel. They died so they could be married to another. The dead in Hades died so they could be married to another. They were the 144,000 first fruits, who followed the Lambkin where ever he went, etc.
They became the New People Bringing Forth the Fruit Thereof, the Kingdom of God, etc. and the gentiles that followed were like the gentiles that joined Israel according to the flesh.
So, the bottom line is, “So, all Israel will be saved” is the conclusion to the apparent problem, that it appears that Israel won’t be successfully saved:
[Romans 9:1-6 NASB20] (1) I am telling the truth in Christ, I am not lying; my conscience testifies with me in the Holy Spirit, (2) that I have great sorrow and unceasing grief in my heart. (3) For I could wish that I myself were accursed, [separated] from Christ for the sake of my countrymen, my kinsmen according to the flesh, (4) who are Israelites, to whom belongs the adoption as sons [and daughters,] the glory, the covenants, the giving of the Law, the [temple] service, and the promises; (5) whose are the fathers, and from whom is the Christ according to the flesh, who is over all, God blessed forever. Amen. (6) But [it is] not as though the word of God has failed. For they are not all Israel who are [descended] from Israel;
IE: The promise has not failed, it only referred to the remnant.
I will try to answer any questions/objections I may have raised.
Peace.