Everything in Revelation is symbolic, and the reference to writing the divine name on the forehead is a symbolic reference to Tetragrammaton on the headband of the high priest. I don’t know what you’re intending to dispute here, that the high priest wore a headband with the divine name, or that the author had this in mind, or that we should notice the connection?
In terms of the use of the divine name in the book of Revelation check out the work of Gerard Mussies and Sean McDonough, in particular: Sean McDonough (1999). YHWH at Patmos: Rev. 1: 4 in Its Hellenistic and Early Jewish Setting. Mohr Siebeck.
https://www.amazon.co.uk/YHWH-Patmos-Hellenistic-Jewish-Setting/dp/1610971558