It seems to me, such an insistence of a distinction between Jews and Gentile believers in Jesus, lends itself to a kind of racism...and, in dispensational eschatology, in a short time would be self-defeating.
After all, if Israel is serving Christ for 1,000 years...and "in Christ there is no...Jew or Gentile" than the Jewish followers of Jesus would intermarry with the Gentile ones (as has happened now for 2000 years)...and there would be no distinction possible (over time) between Jew and Gentile...as all would be submitted to Christ.
Given the same religion, without some sort of assumed miscegenation (separation) of races (which certainly was assumed when dispensationalism developed)...separate Jewish identity would soon vanish.
The only reason for a continued separate Jewish people today--is their majority rejection of Jesus as Messiah. Had they accepted Christ, while some Jewish names and customs may remain, the Jews as a separate people-group would not exist.
Hey I have not seen you in so long!