In Frederic Louis Godet takes a “National Election” approach in his commentary on Romans 9. He summarizes the flow of Romans 9-11 as follows: “1. That of God's absolute liberty in regard to every alleged required right, upon Him, on man's part; this is the subject of chap. ix. 2. That of the legitimacy of the use which God has made of His liberty in the case in question; such is the subject of chap, x., where Paul shows that Israel by their want of understanding drew upon themselves the lot which has overtaken them. 3. That of the utility of this so unexpected measure: this forms the subject of chap, xi., where the beneficent consequences of Israel's rejection down to their glory one final result are unfolded.” Godet explains the chapter verse by verse and along the way he picks apart the grammatical details to draw out Paul’s point. The OT examples of Isaac, Jacob, and Moses are not talking about eternal salvation, but rather God’s merciful (but not arbitrary) choice to reveal Himself and bless them. Godet sees the election of Jacob as primary national, but also teaching that God chooses to justify by faith. Godet summarizes the chapter as: “The word of God has not therefore been made of no effect by the fact of the rejection of the Israelitish nation (ver. 6). For, 1st, the principle of divine selection which controlled the early destinies of the patriarchal family is only realized anew in the distinction between believing Israelites and the carnal and rejected mass (vv. 6-13). 2d. God, when making choice of this people to prepare for the salvation of the world, did not abdicate His freedom to reject them on certain conditions, and if lie came to think this good ; neither did He abdicate His liberty of calling other individuals not belonging to this people, on certain conditions, and if He came to see good reason. And the use which He actually makes of this liberty, in rejecting His obstinately rebellious people while sparing them as long as possible, and even after the greatest crimes, is not tantamount to the annulling of His word (vv. 14-24).”
The two big takeaways I had were: 1) National Election and Corporate Election explanations of Romans 9 are not mutually exclusive and 2) Godet is the best at “grammar analysis” that I have seen so far.