Mistwharf (Hard) is the best map imo! It has the most big chest spawns and Su Yi can navigate it quickly. Also, go for the 2.5x multiplier buff, preferably the exotic one but rare works too if your luck on the buffs is bad

Avoid the final boss and go for the 10k offering, make sure to prioritize items by their per-slot value and organize them neatly (I do squares on the left and sideways rectangles on the right)