I want a RAW D&D mode. No Larian house rules.
Thats not an issue Larian needs to address though. Theres always fan modders around who make such mods. They existed for BG1+BG2, too. No regular programmer is such a stiffler for rules than these people and basically unlimited time to implement them.
So all Larian has to do for this is to allow modding of the game.
By the way any reallife DM I ever met had house rules. I dont mind them as long as they make sense, or preferably improve balance.