For the first experiment, a level 60 character with 3453 CP was taken. We checked 4 locations of the Abandoned Iron Mine Work Site, Cron Castle, Cron Castle Entrance and Marni's Underground Facility.
Below you will find a table with the received drop and video as evidence. Unfortunately at Marni we used a different build skill. But despite this, the best location was the Cron Castle Entrance in which we destroyed the most monsters
We can conclude that it is best to farm in that location where the monsters are the weakest, while they must remain orange for 200% drop
We also recommend watching a similar experiment from Legit Mobile