Administrative boundaries are the second part of the new map features for v1.3, and they are now implemented. But drawing this new vector data highlighted performance problems already present in v1.2, so work has been started to overhaul and optimize the line drawing code in the the game. The new tag and category system was also started in September. This feature is the last one scheduled to be implemented before v1.3 is made a public beta, so the v1.3 beta release is much closer now.
https://carloscarrasco.com/nimby-rails-september-2021/