I tested Essence farming, it's bugged.

I tried essence farming using three tablets, each with the modifier "Map contains an additional Essence," plus around 300–400% increased chance for maps to contain essences from the Atlas passive tree. I also tested without the Atlas tree nodes. In every case, maps spawned exactly three essences (sometimes only two, for some reason), but never four or five.

I have been running essence maps the last half-day and only getting one essence regardless of the number of essences in maps from tablets and % increased essences in map.