Author of the Increased Stack Mod: Taveron
The Increased Stack Mod increases the capacity of stacks by 10 times. Stacks with meat, hides and drugs remained unchanged.
This mod is compatible with existing saves, it does not require you to start a new game.
Increased Stack Mod Review
If it bothers you that your storage areas get filled with different piles of the same resource, the Increased Stack Mod will allow you to pile them up in larger stacks for better storage management.