[Map✓] Does a "Region map" editor exist?

Hi guys! I'm new here. I'm building my own hack rom from scratch using decomp Pokeeemerald. Everything is great, I'm replicating my own town (Lido Di Ostia - Rome) but now I need to modify the region map. I know there are several tools for that but they are implemented on the rom binary version.
Is there a way to modify the region map using decomp & disassembly?

Thanks in advice!

Porymap has a region map editor built in.
Tools > Region Map Editor

You can find Porymap here

The region map editor is not released, yet. It will be included in an upcoming Porymap 1.2.2 release sometime in the next week. There are some last couple bugs that are being addressed right now.

That explains smth a friend brought up, guess I have the version with the current region map editor.

Thanks! Have you got any news about the new version?

1.2.2 is now out, with a region map editor.

https://github.com/huderlem/porymap/releases