It is quite likely that the heavenly witnesses verse contributed to the Trinity formulations phrasing. In the Latin west, that would be direct, in the Greek east, the manuscripts were split, yet even where absent, the thoughts and ideas of the verse were in play. The interpretations could vary widely.
1 John 5:7 (AV)
For there are three that bear record in heaven,
the Father, the Word, and the Holy Ghost:
and these three are one.
There is solid evidence that the verse was actually considered too Sabellian.
One of the clearest explanations comes from Eusebius writing to Marcellus of Ancyra.
This text is given in the 2017 thesis at Groningen by Jeroen Beekhuizen - "The Comma Johanneum revisited". The thesis supervisor was Professor Geurt Hendrik van Kooten, now at Cambridge.
From The Comma Johanneum revisited - p. 6
Eusebius 11 (fourth century) has an interesting passage which may be a reference to the Comma. In his Ecclesiastical Theology where he refutes some Sabellian opinions of Marcellus he says:
"[To say] that the Father is the same as the Word inside him, and that his Son is the Word inside him is the mark of the heresy of Sabellius. So again also the saying that the Three are One (τὸ λέγειν τὰ τρία <ἓν> εἶναι), the Father and the Son and the Holy Spirit; for this is also of Sabellius (Σαβελλίου γὰρ καὶ τοῦτο)."
Although I am not claiming that Eusebius quotes the Comma here, his phraseology is remarkable. He could have said 'saying that the Three are One is also of Sabellius', but now he adds his last clause in a way that puts special emphasis on the saying 'that the Three are One' - 'for this is also of Sabellius'. Whether Eusebius had the Comma in mind or not, it is clear that the language of the Comma could be regarded as Sabellian.
11 Eusebius of Caesarea, De Ecclesiastica Theologia3.3-3.4 (PG 24:1001-1004c).
Jeroen was conservative in his conclusions. Imho, this text from Eusebius likely related to the heavenly witnesses controversies, with some Greek manuscripts supporting the verse inclusion, others with the omission. This Eusebian tension on the verse was written about by Frederick Nolan (1784-1864), long before the Eusebius quote above was discovered. I do not think it is any other publication, not even Grantley McDonald's Raising the Ghost of Arius.
Granted, this idea of early Greek manuscripts with the verse is considered close to heretical by modern textual criticism, however you do have to follow the many evidences and avoid reaching hasty conclusions.
Much more could be said, including the Arians singing about the "three are one".
For now, the above es suficiente.