Thanks for your post.

.
I’m not especially interested what the early Church fathers taught
Well, you may not be, but certainly the governing body is, your teaching authority. The following are a collection of verses taken from the Watchtower (prof texted by them to try and support that the fathers were Trinitarian):
*Jesus himself said: “Eternal life is this: to know you, the only true God, and Jesus Christ whom you have sent.” So our entire future hinges on our knowing the true nature of God, and that means getting to the root of the Trinity controversy.
Various Trinitarian concepts exist. But generally the Trinity teaching is that in the Godhead there are three persons, Father, Son, and Holy Spirit; yet, together they are but one God. The doctrine says that the three are coequal, almighty, and uncreated, having existed eternally in the Godhead.
If the Trinity is true, it is degrading to Jesus to say that he was never equal to God as part of a Godhead. But if the Trinity is false, it is degrading to Almighty God to call anyone his equal. If the Trinity is false, it dishonors God to say, “We worship one God in Trinity.”
The ante-Nicene Fathers were acknowledged to have been leading religious teachers in the early centuries after Christ’s birth. What they taught is of interest.
Justin Martyr, who died about 165 C.E., called the prehuman Jesus a created angel who is “other than the God who made all things.” He said that Jesus was inferior to God and “never did anything except what the Creator…willed him to do and say.”
Irenaeus, who died about 200 C.E., said that the prehuman Jesus had a separate existence from God and was inferior to him. He showed that Jesus is not equal to the “One true and only God,” who is “supreme over all, and besides whom there is no other.”
Clement of Alexandria, who died about 215 C.E., called Jesus in his prehuman existence “a creature” but called God “the uncreated and imperishable and only true God.” He said that the Son “is next to the only omnipotent Father” but not equal to him.
Tertullian, who died about 230 C.E., taught the supremacy of God. He observed: “The Father is different from the Son (another), as he is greater; as he who begets is different from him who is begotten; he who sends, different from him who is sent.” He also said: “There was a time when the Son was not….Before all things, God was alone.” (The word “tri’as” appears in its Latin form of “trinitas” in Tertullian. While these words do translate to “Trinity,” this is no proof in itself that Tertullian taught the doctrine of the Trinity.)
Hippolytus, who died about 235 C.E., said that God is “the one God, the first and the only One, the Maker and Lord of all,” who “had nothing co-eval [of equal age] with him….But he was One, alone by himself; who, willing it, called into being what had no being before,” such as the created prehuman Jesus.
Origen, who died about 250 C.E., said that “the Father and Son are two substances…two things as to their essence,” and that “compared with the Father, [the Son] is a very small light.”
The testimony of history makes clear that the Trinity was unknown for several centuries after biblical times. Thus, those who believe in the Trinity are not “holding God in accurate knowledge.”
Soon, when God brings this present wicked system of things to its end, Trinitarian Christendom will be called to account. And she will be judged adversely for her God-dishonoring actions and doctrines. By honoring God as supreme and worshiping him on his terms, Jehovah’s Witnesses can avoid the judgment that he will soon bring on apostate Christendom.*
The “Insight to the Scriptures” uses the church fathers as reference sources in areas of the two books.
So if the Watchtower has no problem “using” them, why would you?