You can choose between regular and "FORCED" presets. Difference between them is a bit tricky to explain, but here's how the game selects the chest quality:
1 - Calculate luck for gold chest, if success exit with gold quality, else process next step
2 - Calculate luck for silver chest, if success exit with silver quality, else process next step
3 - Calculate luck for bronze chest, if success exit with bronze quality, else process next step
4 - Bad luck, exit with no chest
Regular presets of this mod only change the last step. So even if you select the "Gold quality" preset, you'll still get a silver chest if the game succeeded the step 2.
FORCED presets bypass the entire process, so that you'll be guaranteed to get gold chests, but the downtime is that it can break some quests which require you to loot key items that appear only in bronze or silver treasures!
My advice: only use "FORCED" presets for end-game farming.