Friday is for Ad Fontes: Hellenistic Synagogal Prayers

I've recently been reading over the collection of Hellenistic Synagogal Prayers (James H. Charlesworth OTP 2.671-97). These prayers are taken from Books Seven and Eight of the Apostolic Constitutions and it is often argued that they are Jewish prayers with Christian interpolations. D.A. Fiensy (following Kohler, Bousset, and Goodenough) regards these prayers as reflecting a Jewish origin and he supposes that they "seem Jewish because of what they fail to say", there is "often very little peculiarly Christian content", and the Christian elements appear loosely connected to the context. Thus, there is a reasonable argument in favor of Jewish authorship for some of the prayers.

However, the argument for silence is not convincing as Hebrews 11 quotes a stack of Jewish heroes with no reference to Christ either, Christian authors could replicate or rehearse Old Testament patterns since it was part of their sacred literature, and I would contest whether the obvious Christian elements are interpolations when they seem organic to the whole. I don't see any reason why these prayers could not have been produced by a Christian with a Jewish background or else by a Christian immersed in the Psalms.

Prayer 1 (AposCon 7.26-1-3) reads:

Then after communion, you shall give thanks in this way:
We give thanks to you, O God and Father of Jesus our Savior
on behalf of your holy name which you caused to encamp among us,
and on behalf of the knowledge and faith adn love and immortality which you gave to us through Jesus your Son.
O Master Almighty, the God of the universe.
you created the world and what is in it through him
and you planted deeply in our souls a law;
and you prepared for me in the things (necessary) for communion;
(you are) the God of the holy and blameless ones, our fathers Abraham and Isaac and Jacob, your faithful servantts;
the power God, the faithful and true One, without falsehood in your promises;
the One who sent forth upon earth Jesus your Christ, to live together with me as a man, being divine Word and Man, radically to destroy error.
(trans. D.R. Darnell).

Italicised parts are the elements that Darnell regards as Christian interpolations. Strangely, line verse 2 which states that God's holy name came to "encamp among us" clearly echoes John 1:14 and is not regarded as an interpolation or gloss.