Makes you get less monster loot/materials after a quest. Get your grind back on. Updated for Sunbreak (if using base game, use old versions). Drag the folder of the version you wish to use into the Fluffy Manager MHRise Mods folder.

Different versions:
Decreased Monster Rewards:
Get between 1-4 extra monster rewards per item drop slot (a total of five) after a quest. More likely to get less items.

Decreased Monster Rewards Slightly Harder:
Get between 0-4 extra monster rewards per item drop slot (a total of five) after a quest. More likely to get less items, with the max number for more slots being even less than the regular version.

Decreased Monster Rewards Hard Version:
Only get 1 extra monster rewards per item drop slot (a total of five) after a quest. 

Decreased Monster Rewards Harder:
Get between 0-1 extra monster rewards per item drop slot (a total of five) after a quest. 

Decreased Monster Rewards Hardest:
Get no extra monster rewards after a quest, only what you carved or your palico picked up. Unsure if there are only quest item drops; use at your own risk!

Packed for Fluffy Manager. Use only one file. (They will overwrite each other).

Compatibility: Will conflict with any mod that edits the MainTargetLotNumDefineData.user.2 file (path: natives/STM/data/Define/Quest/System/QuestRewardSystem/MainTargetLotNumDefineData.user.2). That mod's changes will need to be added to this mod's file, or vice versa. Anyone is free to copy this mod's changes to their own, if they so wish.

My other mods:
Increased Item Prices
Increased Argosy Prices and Enhanced Argosy Items
Weaker Palico and Palamute Weapons

Permissions:
Don't sell it or put it behind a paywall. Otherwise, do as you wish with it.