Have you ever considered taking on N. T. Wright's assessment of Romans 11:25ff point for point. I would love to hear your response to his interpretation. Where are its weaknesses, its strengths? What are the unknowns? For instance, I read both your commentaries and both of you go into detail about how "kai houtos" is either timing (you) or manner (Wright). You make a strong case with references and so does he. Wright adds something strong when he says "the Greek houtos simply does not bear this sense" as to timing, saying also it "never comes close to meaning this." He then follows this up with a slew of biblical references to make his point, even noting that houtos is never used in a temporal fashion in its other references within Romans.
But you go into detail as well as to the fact that kai houtos can be used in a temporal fashion, noting extra biblical sources. But then you show a few biblical passages that, in fact, show that kai houtos can be used as a temporal phrase! This is where readers like myself get confused :)
Both of you make very good arguments and they have the power to win the readers mind, but both of you cannot be right in the end. I'm OK with a passage remaining unclear but both of you take very strong positions on your stances. Wright even admits that he once held your view until later exegesis of the overall theme of the "one family" made out of both Jews and Gentiles became the interpretive grid of this passage for him and changed him to his present position. Curious.