Uh, really? Didnt realize this was an obscure element. Holding a key (alt , tab...) auto showing containers has been a stable of nearly all cRPGs for the last 30 years...and of course Its the same for Baldurs gate 1 and 2.
Ok. That was kinda rude. Yes. I know its an RPG staple. With all the people complaining about searching empty containers, etc., and the fact that there is no mention of what key to press to activate this, including no keybind or keyboard map, I thought Larian hadn't put it in the game and that was the whole point of me suggesting what I did.
They told me about how to highlight characters, just not items.