Only good for the first playthrough though, unless we add some type of random element.
Otherwise the second time time you have the encounter (which seems like a given in larian mechanics) you will already know.
Also it's generally not too difficult to guess weaknesses when they exist. whaat? the ice monster doesn't like fire? spoilers.
Same with table top. But there is a gentleman's rule: only use character knowledge instead of player knowledge.
To the OP. A great idea. I myself am deliberately ignoring current implementation of EXAMINE, cause it feels like cheating.