I have a spreadsheet to know what day I will finish a farm, playing with the node recharges to get to the character Event (In this case Maul), that way I always finish the farm before the event, all this using the well known 1/3 drop rate.
I dont see a change in the drop rate, the days calculate from the excel and the day actually ending the farm, is almost the same (1-2 days of difference); even kleya is looking like 1/3 drop rate (give or take), for what I can tell with the 2 weeks farm.
And always remember the "law of great numbers" in this cases.