@JupiteronMars Personally, I think the way they handled it in TW2 gave the potion system more character and made it feel unique. The issue was that you either couldn't really investigate what you were about to fight, or the time it took you to get from the last place you could drink a potion to the actual fight you were preparing for was too long, wasting the potion effects.
What they had planned initially for TW3 - drinking potions prior to battle like in TW2, but activating them only when you've reached that battle so that the effect isn't wasted - was a nice compromise, the biggest issue being the contrived explanaton, not so much the mechanics behind it. Since there's an investigation part added to monster fights, that shouldn't be an issue either. They probably have a good reason for changing their approach though.
Yes, in TW2 it was really well handled. Just add that bit of in-fight activation and it would be perfect.
To drink a potion during the fight is good if you hadn't any time for preparation like when you're ambushed in a forest by some creepy creatures. But that would also be solved with the activation. I did not remember that when I first replied to Master_Dandelion. I would like to know what changed their mind.