I have suggested a feature to run commands and timelines from the worlds but I understand it may be difficult to plan because overworld has very few things that existing commands would be able to affect. So now, I have another suggestion that may be an alternative way to make more possibilities.
A command that can enable or disable overworlds like you would change that from "Other Settings". I have learned that it does not break anything if you, for example, disable overworld later when you already have built your game even if you have made your own worlds and you can enable overworld later again. So, it seems it doesn't change a format of the game files anyhow and should be easy to change via command prompt when playing which shouldn't make this so complicated to make this feature. Although I can't say for sure it is not complicated to add because I am not a developer for PB but knowing programming some also by myself and the fact that there are something so difficult systems like command prompts and timelines my suggestion here should be easy as some easy fixes for bugs or errors. This would be enough to plan something that I made for ending scenes and credits for a game that have worlds which can be found
here.
"enable overworlds = true" and "disable overworlds = false" may-be.
This may cause how some commands working and change the work of the game but I am sure it would be possible to fix that by ourselves because of already existing conditionals.
