This isn't a case of throwing darts at a dartboard to pick the best 'interpretation' that suits us. Rather, it is a case of understanding what Paul understood to grasp the argument he makes and intended us to understand. Let the scripture Paul cites interpret the scripture Paul speaks.
[Eph 1:3-4] - Blessed is the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ, just as he chose us in him before the foundation of the world, that we should be holy and blameless before him in love
Q. Who did God chose (before the foundation of the world) to be holy and blameless before him in love?
A. [Deut 7:6] - For you are a holy people to YHWH your God; YHWH your God has chosen you to be a people for His own possession out of all the peoples who are on the face of the earth. and
[1 Chr 16:13-15] - O seed of Israel His servant, Sons of Jacob, His chosen ones! He is the Lord our God; His judgments are in all the earth. Remember His covenant forever, The word which He commanded to a thousand generations ..
[Eph 1:5] - .. having predestined us to adoption through Jesus Christ to himself according to the good pleasure of his will,
Q. Who was predestined to adoption?
A. [Rom 9:4] - They are Israelites, and to them belong the adoption, the glory, the covenants, the giving of the law, the worship, and the promises.
Q. Who is included in “us” in Ephesians 1:3-10
A. The "us" included in Ephesians are the people Paul would have understood to fit the descriptions he gave in his letter, namely those described in [Deut 7:6][1 Chr 16:13-15] & [Rom 9:4] -- neither more nor less.