I haven't played with a rogue in this game yet, and I refuse to bring Astarion into my main party. But I assume that since height advantage exists, a rogue on high ground will basically get sneak attack damage no matter what, right? If this remains, imagine how nasty that would be when we reach Baldur's Gate and we are likely to run into ENEMY rogue archers. Not exactly a concept that would be very creative.
It's one of the reasons I've been against it (future encounters in abstract). We got a preview of what that would be like with the 2nd gnoll fight in patch 3 (when advantage was much easier to get).
I've used Astarion in the Shattered Sanctum battles with him firing arrows with impunity from the rafters. Made all of it a complete joke.
Height advantage/disadvantage has to go. Without a doubt.