It really isn't much to ask. There's a core rules setting in BGEE, so I don't see why they can't simply incorporate that into gameplay. Perhaps they could include adjustable settings for similarity to DOS2, or adjust difficulty based upon similarity, if that's to the player's fancy (even though this is a D&D game and imo that would be sacrilegious).
Perhaps that WOULD be hard to implement though? I don't know. I sure am hoping a true to ruleset implementation/option set will be available.