We’ve been here before, and that thread was closed because the discussion had been going in circles. No point of continuing in circles here, with the same lack of outcome.
Regarding the question of more IPv6-enabled zones, @Ask wrote in that previous thread that he then was finishing cleaning up after the infrastructure move earlier this year, and working on the migration to PostgreSQL, and when that is done, IPv6 for more zones would be next.
The PostgreSQL update is available on the beta site, and when there’s no reports of issues in the coming weeks, it’ll get pushed to the production site, and likely will need some stabilization there. But then, once that is done, and while there’s no specific date yet, it seems to me that IPv6 enabled on more zones is starting to get within reach - without need to keep pushing, just a bit more patience maybe (compared to the wait so far).