Yes, we are familiar with Darby's theories. Quoting him does not really help.
The question is, how do you distinguish between the remnant in the Church and some other remnant without being entirely artificial? E.g., why the need to divide “all Israel” up into distinct chunks?
Do you suggest that any biblical Christian would suggest that "On this rock I will build my Church" did not include the Jewish Apostles themselves?
Absolutely not. It is my argument that every Jewish believer in Jesus Christ is the remnant of Israel (“all Israel” if you will) and is being saved during the time in which we live. They are the Church, along with their gentile brethren. Natural and wild grafted into one root, Jesus Christ.
In fact you are making the non-dispensational case very well.
It was a Ryrie Study Bible Quote...not Darby.
And I’m not including all of “modern Israel” as part of the remnant. The remnant are those in “that day” who will say “blessed is He who comes in the name of the Lord.”
Amen. "All one in Christ Jesus."