Just understand that calling the times of the Gentiles a parenthesis, is not creating another plan. It is showing that the times of the Gentiles is a gap/time frame where Daniel 9 is on pause, while Jesus gathers the flock of another fold that isn't His. That is to say, the one's who "are His" are those of Israel, since Israel is God's chosen people. He made them His. It is in name only, while only those who are descendants of Abraham through Isaac are His adopted children in Israel. His elect within the nation of Israel.
Again, there is only ONE PLAN. Why would you say that a fellow brother, saved by the blood of Christ, believes there is more than one way of salvation? Slander them who are just as saved as you are, by saying they are heretics because of some supposed belief that they believe God has two plans of redemption, with only one being through Christ?