Unfortunately this one interview is the only information we've been told about modding support for Baldur's Gate 3. He says here that it will allow us to create custom environments. Most likely it'll be similar to Divinity Original Sin 2's toolset, as Baldur's Gate 3 runs on an upgraded version of it's engine.
Originally Posted by Red Spot Sylphin
Could these tools simplify modding?
Very likely if Larian is still working on it, it would allow for the same level of modding support DOS2 allowed for. Which was creating custom modular adventures. Which is something we cannot currently do.
Originally Posted by Red Spot Sylphin
I still can't find a way to create new origins character. All my attempts to add a new entity into the origins section of character creation have no effect or just break the character creation completely.
DOS2's tools allowed for creating custom origin characters or even bypassing the origin system altogether and starting the player off as a preset character.