So I banished everything but Jocks, and I ran 134% item drop with love bugs disabled for around 10 turns. I didn't get any common Jock drops (two sets had dropped already).
I even got a shot of meteor item for +15% item (putting me at 149%), and I received nothing. I then tested 149% items for ten turns. Nothing: https://gyazo.com/ee6b18a2879bfb4a0318f46360f9f55f
As soon as I went to 150% +item%, the commons dropped immediately.
I am going to call this conclusive, and that any anomalies were my user error/rounding issues. I.e., 3rd common drop is 20%.
I am now going to spend my remaining turns at 149% item drops and wait for a clue to drop (assuming it rounds).
EDIT: Spent 25 turns at 149% item drops in A-Boo Peak, and nothing dropped. I'll keep trying this during aftercore for a bit.
Last edited by Aenimus; 05-17-2019 at 10:44 AM.