aqwesed....You made a good catch, my remark about the 'second half' having not been quoted/referenced was not specific enough. I was referring to the 'firstborn' aspect in particular. But you are very correct, the author of the prolog of Rev absolutely interprets the looking to and mourning elements as eschatological. It was just a passing observation that use of the Zecheriah 'firstborn' element didn't appear more, this surprised me.
Your Justin Dial. 118 quote is apparently AI creativity. It actually reads:
So that you ought rather to desist from the love of strife, and repent before the great day of judgment come, wherein all those of your tribes who have pierced this Christ shall mourn as I have shown has been declared by the Scriptures.
No mention of the firstborn element, odd isn't it?
Likewise your Irenaeus 4.33.15 reference (actually 4.33.11) basically repeats Rev 1:7 in both linking Dan 7 and applying the snippet form the first part of Zech.12:10 eschatologically, not as John does (as you acknowledged I think) There is no mention of the second half (and specifically the 'firstborn') that I can see.
Also, the Epistle of Barnabus makes no quote or reference to Zechariah 12:10 at all. ..........AI fakery.