What's the Diminishing Return Threshold?
I’ve heard 30m.
If you’re farming lodestones, I’ve also heard they nerfed Charged Lodestone farming.
https://forum-en.gw2archive.eu/forum/game/gw2/Change-in-loot-parameters-or-a-bug-Merged
You might be interested in reports in this thread. A very fishy thing has been going on with loot chances, many people (including me) blame it on DR parameters. Doesn`t look like it is 30m actually.