I assume that you are lvl 5 in the release game at least when you reach Grimforge which would make combat a lot different.
For me the most difficult fight was when I entered the temple with lvl 3 after having fought the goblins at the temple entrance with wasting a lot of slots because I thought that the goblins behind the door did not know about the fight, then being attacked by Mutt and all her followers, soon from high ground (during the "advantage" times). That was epic, for my taste. The most annoying fight for me always is the hag fight. I hate it.The first time I luckily long rested before it because I was wasted after the masks and thought, the worst is still to come. Nevertheless I lost the fight, one of the three party wipes I suffered while playing. I came back with Gale and Magic Missiles. BTW Magic Missiles only work if you are in range and alive which is not always the case, I almost lost the bloody hag fight during my latest playthrough because of this. BTW did they change Bernard (I had a longer game pause)? I found the fight always easy but lately he killed two of my party members with ease in the only two rounds he was in the fight.
Generally I find the difficulty is ok in the game. As items I use hp potions freely (without throwing them, stupid feature ...) but nothing else. I never dipped weapons for example and never will. I also don't use surfaces, I hated them already in DOS2. I'm not a DnD or BG player, but I like the DnDish combat here more or less. I think some Larian homebrew is a good thing, some is not from what I read, but as a whole it's more enjoyable for me than DOS2.
My expectation for the release game is that you can manage fights from normal gameplay aka playing the story, without knowing the enemies before and using artificial positioning, using the character and group abilities only without barrelmancy or such stuff, on "Normal" difficulty. So before fighting for example the goblin leaders,the spiders, the Minotaurs etc., looking for positions is ok, as you know that they are enemies to fight. With the Gith it's not ok because you don't know wether they are enemies or not, the fight should start from the dialog.
