Ha! Bespoke RPG engine is probably one of Larian's biggest assets. As much as I would like to see other studios taking advantage of what they have build I doubt they will be sharing.
I doubt it is engine tailored to be used by community (the way Bethesda or Aurora engine was). And with how high production the game is, Larian was likely to use 3rd party tools as well, and those they couldn't release even if they wanted to.
They did try to licence D:OS Tactics game, but it didn't pan out. I am not sure if they will try producing again anytime soon.
