Baldur's Gate 3 mods enjoyed a new set of tools last year as part of its seventh patch, tools which it only took erstwhile modders two days to unlock. These untapped kits allow these expeditionary tinkerers to create whole new campaigns, in the vein of Skyrim's ambitious mods. At least, in theory.
In practice, it's a little more complicated than that. Since Larian has not officially recognised or condoned these unlocked toolkits, modders have been left on their own to muddle through without proper documentation.