I admire your efforts to make this game better.
However I am not sure the reason why things are not moving, comes from Larian's view on what is balanced.
I am convinced that the combat AI desperately needs those "larianisms" to show some activity. From there it's not that much about providing the player with some "cheese", it's more about giving the AI some elements to demonstrate some abilities and to show a pseudo intelligence. That is not tactically impressive but its adaptative nature allows players to play and replay several fights with a different experience (potentially boring) each time.
In the whole EA part of the game, I am not aware of any fight where the AI would perform well on a flat ground with no interactive object, just relying on the DnD features of the npcs. If they don't do it at low levels, I am afraid they won't do it at higher levels when the number of combinations explode.