There is no attached plugin, I will attach one in the final release
Yeah, every code is region free!
Ok, I'm going to explain this and pin it to the main post.
The chances of shiny pokemon in Ultra Wormholes are calculated differently. If I'm not wrong, the chance is not calculated when you enter a battle, but when you enter the portal to that zone. This means that all the pokemon there will have either 100% chance of being shiny or 0% chance. Because of this, the original cheat does not work. There is not current cheat to do this, and I don't have the ability to create one.
So, this means pokemon like UB are not necessarily shiny locked.
(Not tested)You can try this by entering a portal, saving the game inside the zone and seeing if there is any shiny pokemon. If there is, if you reset the game and fight with that pokemon again, you will see that in fact it's shiny.