Hi KJ,
While experimenting looking for a way to get data for the equipped potion, I discovered that :
ItemLocation.Unknown1 = 21 = current follower offhand
ItemLocation.Unknown2 = 22 = current follower mainhand
Edit :
...and it looks like ItemLocation.MerchantAvaibleItemsForPurchase = 17 is the now the variable for equipped potion.
-------------------> ? ItemLocation.FollowerOffHand ?
-------------------> ? ItemLocation.FollowerMainHand ?
-------------------> ? ItemLocation.PotionSlot ?