Although according to Loki 2x02, there were 802 branches that still existed after Dox's pruning and possibly until the end of the show-onwards.
That doesn't include the timelines that branched off due to the events from What If thanks to Uatu, nor some timelines that could only be branched...
I like to think that 'TRN' and some of the "Phase One" games are part of this timeline (for condensing sake):
https://marvel.fandom.com/wiki/Earth-80734
Hm...
From the newest Peacemaker Presents: Vigilante/Eagly issue.
EDIT: The 2nd story has the DCEU Flash ring. That confirms my suspicion about this being a DCEU-set relic.
I should also mention, I'm not counting the pre-Crisis Swamp Thing stories nor the pre-Crisis Doom Patrol or any of the hundreds of House of Secrets/Mystery stories of yesteryear.
That's supplementary material that has since been historically altered by Crisis on Infinite Earths.
This "Vertigo...
The "Vertigo Universe" is, for all intents and purposes, a Hypertimeline of New Earth but not to where it starts to become its own Earth.
Per Hypertime rules, it will flow back to the main timeline and out of it, then back again. Like a river.
That was my guess is that when first introduced, plans didn't go forward, the public eventually forgot in the following decades, and it only became public again for the reasons given in 25 Moments.